Fixing intrinsics for Windows clang

Windows clang requires that intrinsics be properly declared
through intrin.h, otherwise, intrinsics were getting
manually declared through a pragma instruction from winnt.h
and clang returned an error.

Change-Id: Iddfa4e3d6c76388e986dc445e40fd05359c2763c
Reviewed-on: https://swiftshader-review.googlesource.com/7050
Tested-by: Alexis Hétu <sugoi@google.com>
Reviewed-by: Nicolas Capens <capn@google.com>
diff --git a/src/Common/Timer.cpp b/src/Common/Timer.cpp
index a147c8b..bb01cda 100644
--- a/src/Common/Timer.cpp
+++ b/src/Common/Timer.cpp
@@ -19,6 +19,7 @@
 		#define WIN32_LEAN_AND_MEAN
 	#endif
 	#include <windows.h>
+	#include <intrin.h>
 #else
 	#include <sys/time.h>
 	#include <x86intrin.h>
diff --git a/third_party/LLVM/lib/Support/Atomic.cpp b/third_party/LLVM/lib/Support/Atomic.cpp
index 94760cc..d450879 100644
--- a/third_party/LLVM/lib/Support/Atomic.cpp
+++ b/third_party/LLVM/lib/Support/Atomic.cpp
@@ -17,6 +17,7 @@
 using namespace llvm;
 
 #if defined(_MSC_VER)
+#include <intrin.h>
 #include <windows.h>
 #undef MemoryFence
 #endif