[NFC][libclc] Fix clcfunc.h merge conflict resolve in b400aa4 (#16809)

These 4 macros were moved in 4602c16, but added back by
b400aa4, resuling in duplicate definitions in this file.

Author: wenju-he

libclc/clc/include/clc/clcfunc.h

@@ -18,9 +18,4 @@
 #define _CLC_DEF __attribute__((always_inline))
 #endif
 
-#define _CLC_INLINE __attribute__((always_inline)) inline
-#define _CLC_CONVERGENT __attribute__((convergent))
-#define _CLC_PURE __attribute__((pure))
-#define _CLC_CONSTFN __attribute__((const))
-
 #endif // __CLC_CLCFUNC_H_