[llvm] [CodeGen] Get stack alignment from TargetFrameLowering (PR #105477)

[Sergei Barannikov via llvm-commits]

s-barannikov wrote:

So this isn't an NFC due to two failing tests (now updated).
For i686-unknown, data layout string [specifies](https://github.com/llvm/llvm-project/blob/15b41d207e15c96cf6f6a7e72cbf3c0044762df5/llvm/lib/Target/X86/X86TargetMachine.cpp#L166) "S128" (16-byte alignment), while FrameLowering is constructed with the default alignment of 4 bytes (not overridden by [these](https://github.com/llvm/llvm-project/blob/e8f312de78577e14154c10db0cb71147c182b69a/llvm/lib/Target/X86/X86Subtarget.cpp#L308-L312) checks).

@arsenm Can you take a look what has gone wrong with the AMDGPU test please?


https://github.com/llvm/llvm-project/pull/105477