[llvm] [SPIR-V] Add implementation of G_SPLAT_VECTOR opcode and fix invalid types processing (PR #84766)

[Michal Paszkowski via llvm-commits]

================
@@ -0,0 +1,29 @@
+; This test is to check that two functions have different SPIR-V type
----------------
michalpaszkowski wrote:

Thank you for tackling this one! This was a big (repeating) issue appearing when validating OpenCL CTS kernels. Surprisingly, the same function type definitions did not cause any runtime problems at least in OpenCL CTS.

https://github.com/llvm/llvm-project/pull/84766