[clang] [X86] Update BMI, BMI2 and TBM constexpr tests (PR #156260)

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bursow wrote:

Checked C++14-specific variable declarations within constexpr functions, which were causing compilation errors in the C++11 environment. refactored the code to be C++11 compliant, which resolved the issue also added BMI, BMI2 and TBM constexpr tests. @RKSimon

https://github.com/llvm/llvm-project/pull/156260