Rollback of rL355585.

Rollback of rL355585.

Introduces memory leak in FunctionTest.GetPointerAlignment that breaks sanitizer buildbots:

```
=================================================================
==2453==ERROR: LeakSanitizer: detected memory leaks

Direct leak of 128 byte(s) in 1 object(s) allocated from:
    #0 0x610428 in operator new(unsigned long) /b/sanitizer-x86_64-linux-bootstrap/build/llvm/projects/compiler-rt/lib/asan/asan_new_delete.cc:105
    #1 0x16936bc in llvm::User::operator new(unsigned long) /b/sanitizer-x86_64-linux-bootstrap/build/llvm/lib/IR/User.cpp:151:19
    #2 0x7c3fe9 in Create /b/sanitizer-x86_64-linux-bootstrap/build/llvm/include/llvm/IR/Function.h:144:12
    #3 0x7c3fe9 in (anonymous namespace)::FunctionTest_GetPointerAlignment_Test::TestBody() /b/sanitizer-x86_64-linux-bootstrap/build/llvm/unittests/IR/FunctionTest.cpp:136
    #4 0x1a836a0 in HandleExceptionsInMethodIfSupported<testing::Test, void> /b/sanitizer-x86_64-linux-bootstrap/build/llvm/utils/unittest/googletest/src/gtest.cc
    #5 0x1a836a0 in testing::Test::Run() /b/sanitizer-x86_64-linux-bootstrap/build/llvm/utils/unittest/googletest/src/gtest.cc:2474
    #6 0x1a85c55 in testing::TestInfo::Run() /b/sanitizer-x86_64-linux-bootstrap/build/llvm/utils/unittest/googletest/src/gtest.cc:2656:11
    #7 0x1a870d0 in testing::TestCase::Run() /b/sanitizer-x86_64-linux-bootstrap/build/llvm/utils/unittest/googletest/src/gtest.cc:2774:28
    #8 0x1aa5b84 in testing::internal::UnitTestImpl::RunAllTests() /b/sanitizer-x86_64-linux-bootstrap/build/llvm/utils/unittest/googletest/src/gtest.cc:4649:43
    #9 0x1aa4d30 in HandleExceptionsInMethodIfSupported<testing::internal::UnitTestImpl, bool> /b/sanitizer-x86_64-linux-bootstrap/build/llvm/utils/unittest/googletest/src/gtest.cc
    #10 0x1aa4d30 in testing::UnitTest::Run() /b/sanitizer-x86_64-linux-bootstrap/build/llvm/utils/unittest/googletest/src/gtest.cc:4257
    #11 0x1a6b656 in RUN_ALL_TESTS /b/sanitizer-x86_64-linux-bootstrap/build/llvm/utils/unittest/googletest/include/gtest/gtest.h:2233:46
    #12 0x1a6b656 in main /b/sanitizer-x86_64-linux-bootstrap/build/llvm/utils/unittest/UnitTestMain/TestMain.cpp:50
    #13 0x7f5af37a22e0 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x202e0)

Indirect leak of 40 byte(s) in 1 object(s) allocated from:
    #0 0x610428 in operator new(unsigned long) /b/sanitizer-x86_64-linux-bootstrap/build/llvm/projects/compiler-rt/lib/asan/asan_new_delete.cc:105
    #1 0x151be6b in make_unique<llvm::ValueSymbolTable> /b/sanitizer-x86_64-linux-bootstrap/build/llvm/include/llvm/ADT/STLExtras.h:1349:29
    #2 0x151be6b in llvm::Function::Function(llvm::FunctionType*, llvm::GlobalValue::LinkageTypes, unsigned int, llvm::Twine const&, llvm::Module*) /b/sanitizer-x86_64-linux-bootstrap/build/llvm/lib/IR/Function.cpp:241
    #3 0x7c4006 in Create /b/sanitizer-x86_64-linux-bootstrap/build/llvm/include/llvm/IR/Function.h:144:16
    #4 0x7c4006 in (anonymous namespace)::FunctionTest_GetPointerAlignment_Test::TestBody() /b/sanitizer-x86_64-linux-bootstrap/build/llvm/unittests/IR/FunctionTest.cpp:136
    #5 0x1a836a0 in HandleExceptionsInMethodIfSupported<testing::Test, void> /b/sanitizer-x86_64-linux-bootstrap/build/llvm/utils/unittest/googletest/src/gtest.cc
    #6 0x1a836a0 in testing::Test::Run() /b/sanitizer-x86_64-linux-bootstrap/build/llvm/utils/unittest/googletest/src/gtest.cc:2474
    #7 0x1a85c55 in testing::TestInfo::Run() /b/sanitizer-x86_64-linux-bootstrap/build/llvm/utils/unittest/googletest/src/gtest.cc:2656:11
    #8 0x1a870d0 in testing::TestCase::Run() /b/sanitizer-x86_64-linux-bootstrap/build/llvm/utils/unittest/googletest/src/gtest.cc:2774:28
    #9 0x1aa5b84 in testing::internal::UnitTestImpl::RunAllTests() /b/sanitizer-x86_64-linux-bootstrap/build/llvm/utils/unittest/googletest/src/gtest.cc:4649:43
    #10 0x1aa4d30 in HandleExceptionsInMethodIfSupported<testing::internal::UnitTestImpl, bool> /b/sanitizer-x86_64-linux-bootstrap/build/llvm/utils/unittest/googletest/src/gtest.cc
    #11 0x1aa4d30 in testing::UnitTest::Run() /b/sanitizer-x86_64-linux-bootstrap/build/llvm/utils/unittest/googletest/src/gtest.cc:4257
    #12 0x1a6b656 in RUN_ALL_TESTS /b/sanitizer-x86_64-linux-bootstrap/build/llvm/utils/unittest/googletest/include/gtest/gtest.h:2233:46
    #13 0x1a6b656 in main /b/sanitizer-x86_64-linux-bootstrap/build/llvm/utils/unittest/UnitTestMain/TestMain.cpp:50
    #14 0x7f5af37a22e0 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x202e0)

SUMMARY: AddressSanitizer: 168 byte(s) leaked in 2 allocation(s).
```

See http://lab.llvm.org:8011/builders/sanitizer-x86_64-linux-bootstrap/builds/11358/steps/check-llvm%20asan/logs/stdio for more information.

Also introduces use-of-uninitialized-value in ConstantsTest.FoldGlobalVariablePtr:
```
==7070==WARNING: MemorySanitizer: use-of-uninitialized-value
    #0 0x14e703c in User /b/sanitizer-x86_64-linux-fast/build/llvm/include/llvm/IR/User.h:79:5
    #1 0x14e703c in Constant /b/sanitizer-x86_64-linux-fast/build/llvm/include/llvm/IR/Constant.h:44
    #2 0x14e703c in llvm::GlobalValue::GlobalValue(llvm::Type*, llvm::Value::ValueTy, llvm::Use*, unsigned int, llvm::GlobalValue::LinkageTypes, llvm::Twine const&, unsigned int) /b/sanitizer-x86_64-linux-fast/build/llvm/include/llvm/IR/GlobalValue.h:78
    #3 0x14e5467 in GlobalObject /b/sanitizer-x86_64-linux-fast/build/llvm/include/llvm/IR/GlobalObject.h:34:9
    #4 0x14e5467 in llvm::GlobalVariable::GlobalVariable(llvm::Type*, bool, llvm::GlobalValue::LinkageTypes, llvm::Constant*, llvm::Twine const&, llvm::GlobalValue::ThreadLocalMode, unsigned int, bool) /b/sanitizer-x86_64-linux-fast/build/llvm/lib/IR/Globals.cpp:314
    #5 0x6938f1 in llvm::(anonymous namespace)::ConstantsTest_FoldGlobalVariablePtr_Test::TestBody() /b/sanitizer-x86_64-linux-fast/build/llvm/unittests/IR/ConstantsTest.cpp:565:18
    #6 0x1a240a1 in HandleExceptionsInMethodIfSupported<testing::Test, void> /b/sanitizer-x86_64-linux-fast/build/llvm/utils/unittest/googletest/src/gtest.cc
    #7 0x1a240a1 in testing::Test::Run() /b/sanitizer-x86_64-linux-fast/build/llvm/utils/unittest/googletest/src/gtest.cc:2474
    #8 0x1a26d26 in testing::TestInfo::Run() /b/sanitizer-x86_64-linux-fast/build/llvm/utils/unittest/googletest/src/gtest.cc:2656:11
    #9 0x1a2815f in testing::TestCase::Run() /b/sanitizer-x86_64-linux-fast/build/llvm/utils/unittest/googletest/src/gtest.cc:2774:28
    #10 0x1a43de8 in testing::internal::UnitTestImpl::RunAllTests() /b/sanitizer-x86_64-linux-fast/build/llvm/utils/unittest/googletest/src/gtest.cc:4649:43
    #11 0x1a42c47 in HandleExceptionsInMethodIfSupported<testing::internal::UnitTestImpl, bool> /b/sanitizer-x86_64-linux-fast/build/llvm/utils/unittest/googletest/src/gtest.cc
    #12 0x1a42c47 in testing::UnitTest::Run() /b/sanitizer-x86_64-linux-fast/build/llvm/utils/unittest/googletest/src/gtest.cc:4257
    #13 0x1a0dfba in RUN_ALL_TESTS /b/sanitizer-x86_64-linux-fast/build/llvm/utils/unittest/googletest/include/gtest/gtest.h:2233:46
    #14 0x1a0dfba in main /b/sanitizer-x86_64-linux-fast/build/llvm/utils/unittest/UnitTestMain/TestMain.cpp:50
    #15 0x7f2081c412e0 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x202e0)
    #16 0x4dff49 in _start (/b/sanitizer-x86_64-linux-fast/build/llvm_build_msan/unittests/IR/IRTests+0x4dff49)

SUMMARY: MemorySanitizer: use-of-uninitialized-value /b/sanitizer-x86_64-linux-fast/build/llvm/include/llvm/IR/User.h:79:5 in User
```

See http://lab.llvm.org:8011/builders/sanitizer-x86_64-linux-fast/builds/30222/steps/check-llvm%20msan/logs/stdio for more information.

llvm-svn: 355616