Cherry-pick LLVM 15 patch to fix fpext/fptrunc bf16 crash (#608)

Fix crash compiling following kernel:
float __attribute__((overloadable)) __spirv_ocl_hypot(float x, float y)
{
  return __builtin_astype(0x7FFFFFFF, float);
}
__bf16 __attribute__((overloadable)) __spirv_ocl_hypot(__bf16 x, __bf16
y) {
  return __spirv_ocl_hypot((float)x, (float)y);
}

Add Clang patch adding TargetExtTy support for representing OpenCL/SP…

…IR-V types (#607)

The patch helps us avoid workarounds on LLVM 16 with opaque pointers
enabled. The changes in the patch are part of LLVM 17+.

Add clang patch to enable BFloat16 for SPIR/SPIR-V (#592)

Add clang patch to enable BFloat16 for SPIR/SPIR-V (#591)

[CMake] Preserve non-PATCH brackets in title using git am --keep-non-…

…patch (#596)

(cherry picked from commit c274f33)

[CMake] Preserve non-PATCH brackets in title using git am --keep-non-…

…patch (#597)

(cherry picked from commit c274f33)

[CMake] Preserve non-PATCH brackets in title using git am --keep-non-…

…patch (#598)

(cherry picked from commit c274f33)

[CMake] Preserve non-PATCH brackets in title using git am --keep-non-…

…patch (#599)

(cherry picked from commit c274f33)

[CMake] Preserve non-PATCH brackets in title using git am --keep-non-…

…patch (#600)

(cherry picked from commit c274f33)

[CMake] Preserve non-PATCH brackets in title using git am --keep-non-…

…patch (#601)

(cherry picked from commit c274f33)