Remove include of stdlib.h from SkTypes.h.

Unfortunately, immintrin.h (which is also included by SkTypes)
includes xmmintrin.h which includes mm_malloc.h which includes
stdlib.h for malloc even though, from the implementation, it is
difficult to see why.

Fortunately, arm_neon.h does not seem to be involved in such
shenanigans, so building for Android will keep things sane.

TBR=reed@google.com
Doesn't change Skia API, just moves an include.

Review URL: https://codereview.chromium.org/1313203003
diff --git a/src/pathops/SkOpAngle.cpp b/src/pathops/SkOpAngle.cpp
index 36c0dd9..ac596fd 100644
--- a/src/pathops/SkOpAngle.cpp
+++ b/src/pathops/SkOpAngle.cpp
@@ -809,7 +809,7 @@
 }
 
 bool SkOpAngle::oppositePlanes(const SkOpAngle* rh) const {
-    int startSpan = abs(rh->fSectorStart - fSectorStart);
+    int startSpan = SkTAbs(rh->fSectorStart - fSectorStart);
     return startSpan >= 8;
 }