Include -lpthread on the link line automatically only for C++

test/Driver/nacl-direct.c

Index: test/Driver/nacl-direct.c
diff --git a/test/Driver/nacl-direct.c b/test/Driver/nacl-direct.c
index 080fe3c4d55a4ebaf626fbfc909101e18fa1fb00..e6020c6627657a2c3d5b1363ffc1575a63be54d1 100644
--- a/test/Driver/nacl-direct.c
+++ b/test/Driver/nacl-direct.c
@@ -69,9 +69,9 @@
 // CHECK-ARM-NOV7: "-target-abi" "aapcs-linux"
 // CHECK-ARM-NOV7: "-mfloat-abi" "hard"
 
-// Check C++ include directories
+// Test clang c++ include dirs and link line when using clang++
 
-// RUN: %clang -x c++ -### -o %t.o %s 2>&1 \
+// RUN: %clangxx -### -o %t.o %s 2>&1 \
 // RUN:     -target armv7a-unknown-nacl-gnueabihf \
 // RUN:   | FileCheck --check-prefix=CHECK-ARM-CXX %s
 // CHECK-ARM-CXX: {{.*}}clang{{.*}}" "-cc1"
@@ -82,7 +82,7 @@
 // CHECK-ARM-CXX: "-internal-isystem" "{{.*}}/../arm-nacl/include"
 // CHECK-ARM-CXX: "-lpthread"
 
-// RUN: %clang -x c++ -### -o %t.o %s 2>&1 \
+// RUN: %clangxx -### -o %t.o %s 2>&1 \
 // RUN:     -target i686-unknown-nacl \
 // RUN:   | FileCheck --check-prefix=CHECK-I686-CXX %s
 // CHECK-I686-CXX: {{.*}}clang{{.*}}" "-cc1"
@@ -93,8 +93,7 @@
 // CHECK-I686-CXX: "-internal-isystem" "{{.*}}/../x86_64-nacl/include"
 // CHECK-I686-CXX: "-lpthread"
 
-//
-// RUN: %clang -x c++ -### -o %t.o %s 2>&1 \
+// RUN: %clangxx -### -o %t.o %s 2>&1 \
 // RUN:     -target x86_64-unknown-nacl \
 // RUN:   | FileCheck --check-prefix=CHECK-x86_64-CXX %s
 // CHECK-x86_64-CXX: {{.*}}clang{{.*}}" "-cc1"