[PowerPC][NFC] Move codegen tests to PowerPC from MIR/PowerPC

All tests with -run-pass !=none should not in MIR/, See MIR/README.

```
Tests for codegen passes should NOT be here but in
test/CodeGen/sometarget. As
a rule of thumb this directory should only contain tests using
'llc -run-pass none'.
```

llvm-svn: 371857

diff --git a/llvm/test/CodeGen/MIR/PowerPC/ifcvt-diamond-ret.mir b/llvm/test/CodeGen/PowerPC/ifcvt-diamond-ret.mir
similarity index 100%
rename from llvm/test/CodeGen/MIR/PowerPC/ifcvt-diamond-ret.mir
rename to llvm/test/CodeGen/PowerPC/ifcvt-diamond-ret.mir

diff --git a/llvm/test/CodeGen/MIR/PowerPC/machine-backward-cp.mir b/llvm/test/CodeGen/PowerPC/machine-backward-cp.mir
similarity index 100%
rename from llvm/test/CodeGen/MIR/PowerPC/machine-backward-cp.mir
rename to llvm/test/CodeGen/PowerPC/machine-backward-cp.mir

diff --git a/llvm/test/CodeGen/MIR/PowerPC/peephole-miscompile-extswsli.mir b/llvm/test/CodeGen/PowerPC/peephole-miscompile-extswsli.mir
similarity index 100%
rename from llvm/test/CodeGen/MIR/PowerPC/peephole-miscompile-extswsli.mir
rename to llvm/test/CodeGen/PowerPC/peephole-miscompile-extswsli.mir

diff --git a/llvm/test/CodeGen/MIR/PowerPC/prolog_vec_spills.mir b/llvm/test/CodeGen/PowerPC/prolog_vec_spills.mir
similarity index 100%
rename from llvm/test/CodeGen/MIR/PowerPC/prolog_vec_spills.mir
rename to llvm/test/CodeGen/PowerPC/prolog_vec_spills.mir