Add explicit includes for a few intrinsics.

__halt, __cpuid, _ReadWriteBarrier, and _mm_getcsr are
all declared in intrin.h, see
https://msdn.microsoft.com/en-us/library/hh977022.aspx

The code currently builds fine because undeclared functions are
ok in C code before C99.

BUG=https://crbug.com/592745

Review URL: https://codereview.chromium.org/1778653002
diff --git a/src/shared/platform/win/nacl_exit.c b/src/shared/platform/win/nacl_exit.c
index e84d4e3..05a6fda 100644
--- a/src/shared/platform/win/nacl_exit.c
+++ b/src/shared/platform/win/nacl_exit.c
@@ -4,6 +4,7 @@
  * found in the LICENSE file.
  */
 
+#include <intrin.h>
 #include <stdlib.h>
 #include <stdio.h>
 
diff --git a/src/shared/platform/win/nacl_time.c b/src/shared/platform/win/nacl_time.c
index 98fd25f..5810b9e 100644
--- a/src/shared/platform/win/nacl_time.c
+++ b/src/shared/platform/win/nacl_time.c
@@ -13,6 +13,7 @@
 #pragma comment(lib, "winmm.lib")
 
 #include <windows.h>
+#include <intrin.h>
 #include <mmsystem.h>
 #include <sys/timeb.h>
 #include <time.h>
diff --git a/src/trusted/service_runtime/arch/x86_32/sel_rt_32.c b/src/trusted/service_runtime/arch/x86_32/sel_rt_32.c
index 1371529..5757b6c 100644
--- a/src/trusted/service_runtime/arch/x86_32/sel_rt_32.c
+++ b/src/trusted/service_runtime/arch/x86_32/sel_rt_32.c
@@ -12,7 +12,7 @@
 /*
  * This header declares the _mm_getcsr function.
  */
-#include <mmintrin.h>
+#include <intrin.h>
 #endif
 
 #include "native_client/src/shared/platform/nacl_log.h"
diff --git a/src/trusted/service_runtime/sel_ldr.c b/src/trusted/service_runtime/sel_ldr.c
index 1fdbadd..cb26e54 100644
--- a/src/trusted/service_runtime/sel_ldr.c
+++ b/src/trusted/service_runtime/sel_ldr.c
@@ -10,6 +10,11 @@
  * NaCl Simple/secure ELF loader (NaCl SEL).
  */
 #include "native_client/src/include/build_config.h"
+
+#if NACL_WINDOWS
+#include <intrin.h>
+#endif
+
 #include "native_client/src/include/portability.h"
 #include "native_client/src/include/portability_io.h"
 #include "native_client/src/include/portability_string.h"