Add support for the 'freeze' instruction (#82979)

This PR is to add support for the 'freeze' instruction:
https://llvm.org/docs/LangRef.html#freeze-instruction

There is no way to implement `freeze` correctly without support on
SPIR-V standard side, but we may at least address a simple (static) case
when undef/poison value presence is obvious. The main benefit of even
incomplete `freeze` support is preventing of translation from crashing
due to lack of support on legalization and instruction selection steps.