Move immintrin/arm_neon includes to where they are used.

src/core/SkSharedMutex.h

Index: src/core/SkSharedMutex.h
diff --git a/src/core/SkSharedMutex.h b/src/core/SkSharedMutex.h
index 21c9f46d64058f28e4d1273d5b40095340a8a4dd..3e8c5b072df4e85d28f528024412d69926f7ab21 100644
--- a/src/core/SkSharedMutex.h
+++ b/src/core/SkSharedMutex.h
@@ -14,6 +14,16 @@
 
 #ifdef SK_DEBUG
     #include "SkMutex.h"
+
+    // On GCC 4.8, targeting ARMv7 with NEON, using libc++, we need to typedef float float32_t,
+    // (or include <arm_neon.h> which does that) before #including <memory> here.
+    // This makes no sense.  I'm not very interested in understanding why... this is an old,
+    // bizarre platform configuration that we should just let die.
+    #if defined(__GNUC__) && __GNUC__ == 4 && __GNUC_MINOR__ == 8 \
+     && defined(SK_CPU_ARM32) && defined(SK_ARM_HAS_NEON)
+        typedef float float32_t;
+    #endif

[bungeman-skia, 2016/06/09 19:55:33]

Can we add libc++ to this

#include <ciso646>

#if defined(_LIBCPP_VERSION) && ...

Also, this covers a lot of files (a lot of files end up pulling in this header).
I assume that doing this here is having an effect in multiple translation units,
though maybe not since this is probably a compiler issue and this is debug only
(the release build is ok!?).

[mtklein_C, 2016/06/09 20:19:43]

Yep, done.
I believe 2 files in Skia and 2 more test-only files include this header.

It appears that no one tests the release build for this platform.
So as you might guess, it is currently broken, and this CL does nothing to
change that.

+
     #include <memory>
 #endif  // SK_DEBUG