[Support] Remove unneeded __has_include fallback
This is a C++17 feature implemented in all supported compilers.
Pull Request: https://github.com/llvm/llvm-project/pull/104898
diff --git a/llvm/include/llvm/Support/Compiler.h b/llvm/include/llvm/Support/Compiler.h
index d8e3794..9d8607f 100644
--- a/llvm/include/llvm/Support/Compiler.h
+++ b/llvm/include/llvm/Support/Compiler.h
@@ -39,10 +39,6 @@
# define __has_builtin(x) 0
#endif
-#ifndef __has_include
-# define __has_include(x) 0
-#endif
-
// Only use __has_cpp_attribute in C++ mode. GCC defines __has_cpp_attribute in
// C mode, but the :: in __has_cpp_attribute(scoped::attribute) is invalid.
#ifndef LLVM_HAS_CPP_ATTRIBUTE
