[Frontend] Avoid including default system header paths on Fuchsia

These paths aren't used and don't make sense on Fuchsia.

Differential Revision: https://reviews.llvm.org/D43992

llvm-svn: 326542
diff --git a/clang/lib/Frontend/InitHeaderSearch.cpp b/clang/lib/Frontend/InitHeaderSearch.cpp
index a098b6a..0506975 100644
--- a/clang/lib/Frontend/InitHeaderSearch.cpp
+++ b/clang/lib/Frontend/InitHeaderSearch.cpp
@@ -216,6 +216,7 @@
     case llvm::Triple::NaCl:
     case llvm::Triple::PS4:
     case llvm::Triple::ELFIAMCU:
+    case llvm::Triple::Fuchsia:
       break;
     case llvm::Triple::Win32:
       if (triple.getEnvironment() != llvm::Triple::Cygnus)
@@ -322,6 +323,7 @@
   case llvm::Triple::RTEMS:
   case llvm::Triple::NaCl:
   case llvm::Triple::ELFIAMCU:
+  case llvm::Triple::Fuchsia:
     break;
   case llvm::Triple::PS4: {
     // <isysroot> gets prepended later in AddPath().