Added #define __has_builtin into block_to_imp.c.
Added #define __has_builtin into block_to_imp.c.

davidchisnall/libobjc2,crystax/android-vendor-libobjc2,ngrewe/libobjc2,darlinghq/darling-libobjc2,gnustep/libobjc2,ngrewe/libobjc2,darlinghq/darling-libobjc2,gnustep/libobjc2,crystax/android-vendor-libobjc2,davidchisnall/libobjc2