[Driver][Haiku] Add /boot/system/develop/headers/gcc/include header path (#140189)

Author: brad0

clang/lib/Driver/ToolChains/Haiku.cpp

@@ -273,6 +273,8 @@ void Haiku::AddClangSystemIncludeArgs(const llvm::opt::ArgList &DriverArgs,
                    "/boot/system/develop/headers/gnu"));
   addSystemInclude(DriverArgs, CC1Args, concat(D.SysRoot,
                    "/boot/system/develop/headers/posix"));
+  addSystemInclude(DriverArgs, CC1Args, concat(D.SysRoot,
+                   "/boot/system/develop/headers/gcc/include"));
   addSystemInclude(DriverArgs, CC1Args, concat(D.SysRoot,
                    "/boot/system/develop/headers"));
 }

clang/test/Driver/haiku.c

@@ -35,6 +35,7 @@
 // CHECK-C-HEADER-PATH: "-internal-isystem" "/boot/system/develop/headers/glibc"
 // CHECK-C-HEADER-PATH: "-internal-isystem" "/boot/system/develop/headers/gnu"
 // CHECK-C-HEADER-PATH: "-internal-isystem" "/boot/system/develop/headers/posix"
+// CHECK-C-HEADER-PATH: "-internal-isystem" "/boot/system/develop/headers/gcc/include"
 // CHECK-C-HEADER-PATH: "-internal-isystem" "/boot/system/develop/headers"
 
 // Check x86_64-unknown-haiku, X86_64