[x86] Exclusion of incorrect include headers paths for MCU target

Exclusion of /usr/include and /usr/local/include headers paths for MCU target.

Differential Revision: http://reviews.llvm.org/D14954

llvm-svn: 255766

clang/lib/Frontend/InitHeaderSearch.cpp

@@ -216,6 +216,7 @@ void InitHeaderSearch::AddDefaultCIncludePaths(const llvm::Triple &triple,
     case llvm::Triple::Bitrig:
     case llvm::Triple::NaCl:
     case llvm::Triple::PS4:
+    case llvm::Triple::ELFIAMCU:
       break;
     case llvm::Triple::Win32:
       if (triple.getEnvironment() != llvm::Triple::Cygnus)
@@ -318,6 +319,7 @@ void InitHeaderSearch::AddDefaultCIncludePaths(const llvm::Triple &triple,
   case llvm::Triple::CloudABI:
   case llvm::Triple::RTEMS:
   case llvm::Triple::NaCl:
+  case llvm::Triple::ELFIAMCU:
     break;
   case llvm::Triple::PS4: {
     // <isysroot> gets prepended later in AddPath().

clang/test/Driver/elfiamcu-header-search.c

@@ -0,0 +1,6 @@
+// REQUIRES: x86-registered-target
+
+// RUN: %clang -target i386-pc-elfiamcu -c -v %s 2>&1 | FileCheck %s
+// CHECK-NOT: /usr/include
+// CHECK-NOT: /usr/local/include
+