[Sanitizers, test] Fix sanitizer tests on Solaris (PR 33274)

[Sanitizers, test] Fix sanitizer tests on Solaris (PR 33274)

Summary:
This patch (on top of the previous two (https://reviews.llvm.org/D40898 and
https://reviews.llvm.org/D40899) complete the compiler-rt side of the the Solaris
sanitizer port.

It contains the following sets of changes:

* For the time being, the port is for 32-bit x86 only, so reject the various tests on
  x86_64.

* When compiling as C++, <setjmp.h> resp. <iso/setjmp_iso.h> only declares
  _setjmp and _longjmp inside namespace std.

* MAP_FILE is a Windows feature.  While e.g. Linux <sys/mman.h> provides a
  no-op compat define, Solaris does not.

* test/asan/TestCases/Posix/coverage.cc was initially failing like this:

/vol/gcc/src/llvm/llvm/local/projects/compiler-rt/lib/sanitizer_common/scripts/sancov.py: 4 files merged; 2 PCs total
rm: cannot remove '/var/gcc/llvm/local/projects/compiler-rt/test/asan/I386SunOSConfig/TestCases/Posix/Output/coverage': Invalid argument

  Further digging revealed that the rm was trying to remove the running test's working
  directory which failed as observed.  cd'ing out of the dir before let the test pass.

* Two tests needed a declaration of alloca. I've now copied the existing code from
  test/asan/TestCases/alloca_constant_size.cc, but it may be more profitable and
  maintainable to have a common testsuite header where such code is collected.

* Similarly, Solaris' printf %p format doesn't include the leading 0x.

* In test/asan/TestCases/malloc-no-intercept.c, I had to undef __EXTENSIONS__
  (predefined by clang for no apparent reason) to avoid conflicting declarations
  for memalign.

* test/ubsan/TestCases/Float/cast-overflow.cpp has different platform dependent
  ways to define BYTE_ORDER and friends.  Why not just use __BYTE_ORDER__ and
  friends as predefined by clang and gcc?

Patch by Rainer Orth.

Reviewers: kcc, alekseyshl

Reviewed By: alekseyshl

Subscribers: srhines, kubamracek, mgorny, krytarowski, fedor.sergeev, JDevlieghere, llvm-commits, #sanitizers

Tags: #sanitizers

Differential Revision: https://reviews.llvm.org/D40900

llvm-svn: 322635