[libclc] remangler generates wrong function _Z22__spirv_GroupBroadcastiDhm when long width is 32

[wenju-he]

Describe the bug

libspirv variants with long_width = 32 contain symbol _Z22__spirv_GroupBroadcastiDhm.
However,
_Z22__spirv_GroupBroadcastiDhm __spirv_GroupBroadcast(int, half, unsigned long)
should be remangled to
_Z22__spirv_GroupBroadcastiDF16_m __spirv_GroupBroadcast(int, _Float16, unsigned long)

_Z22__spirv_GroupBroadcastiDF16_Dv2_m and _Z22__spirv_GroupBroadcastiDF16_Dv3_m symbols are also missing in these long_width=32 bitcodes.

It seems the current logic incorrectly handles the case when both function has both half and long parameters that requires remangling.

This issue is exposed by #21588

To reproduce

Environment

• OS: Windows, Linux
• Target device and vendor: nvptx, amdgpu
• DPC++ version: clang version 23.0.0git (https://github.com/intel/llvm 5ec9fac)

Additional context

No response