Fixes#153304
Changes:
- When writing `ConstantExpr` GEPs to DXIL bitcode, the bitcode writer
will use the old Constant Code `CST_CODE_CE_GEP_OLD = 12` instead of the
newer `CST_CODE_CE_GEP = 32` which is interpreted as an undef in DXIL.
Additional context: [CST_CODE_CE_GEP = 12 in
DXC](0c9e75e7e9/include/llvm/Bitcode/LLVMBitCodes.h (L187))
while the same constant code is labeled [CST_CODE_CE_GEP_OLD in
LLVM](65de318d18/llvm/include/llvm/Bitcode/LLVMBitCodes.h (L411))
- Modifies the `PointerTypeAnalysis` to be able to analyze pointer-typed
constants that appear in the operands of instructions so that the
correct type of the `ConstantExpr` GEP is determined and written into
the DXIL bitcode.
- Adds a `PointerTypeAnalysis` test and dxil-dis test to ensure that the
pointer type of `ConstantExpr` GEPs are resolved and `ConstantExpr` GEPs
are written to DXIL bitcode correctly
In addition, this PR also adds a missing call to
`GV.removeDeadConstantUsers()` in the DXILFinalizeLinkage pass, and
removes an unnecessary manual removal of a ConstantExpr in the
DXILFlattenArrays pass.
13a634281f