[clang][HLSL] Fix include guard typo in hlsl_compat_overloads.h (#164540)
Fixes a typo in the include guard name in hlsl_compat_overloads.h
The incorrect line:
` #define _HLSl_COMPAT_OVERLOADS_H_`
has been corrected to:
` #define _HLSL_COMPAT_OVERLOADS_H_`
Fixes #164100