fast_mutex: disable on x64 compilation
Per Microsoft documentation[1]:
Inline assembly is not supported on the ARM and x64 processors.[1] https://learn.microsoft.com/en-us/cpp/assembler/inline/inline-assembler
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Per Microsoft documentation[1]:
Inline assembly is not supported on the ARM and x64 processors.[1] https://learn.microsoft.com/en-us/cpp/assembler/inline/inline-assembler