[PS4] Fix the unit test to be compatible with clang driver. NFC

".exe" extension is inherently checked by llvm::fs::can_execute()
This patch fixes the linker extension in clang driver and updates the
unit test to accommodate the the check string on windows.

Differential Revision:http://reviews.llvm.org/D15577

llvm-svn: 255814
diff --git a/clang/lib/Driver/Tools.cpp b/clang/lib/Driver/Tools.cpp
index dc125d6..41a4e9a 100644
--- a/clang/lib/Driver/Tools.cpp
+++ b/clang/lib/Driver/Tools.cpp
@@ -10440,7 +10440,7 @@
 
   const char *Exec =
 #ifdef LLVM_ON_WIN32
-      Args.MakeArgString(ToolChain.GetProgramPath("ps4-ld.gold.exe"));
+      Args.MakeArgString(ToolChain.GetProgramPath("ps4-ld.gold"));
 #else
       Args.MakeArgString(ToolChain.GetProgramPath("ps4-ld"));
 #endif