Promote the GCC/libc++/<memory> 'typedef float float32_t' workaround to SkTypes.h

include/core/SkTypes.h

Index: include/core/SkTypes.h
diff --git a/include/core/SkTypes.h b/include/core/SkTypes.h
index 4e95c69f3229cdfc63b95cd2e1fa6bdaeccd8caf..b38268231df1a818d913d559e68e33a0d3dd32b1 100644
--- a/include/core/SkTypes.h
+++ b/include/core/SkTypes.h
@@ -9,6 +9,22 @@
 #define SkTypes_DEFINED
 
 // IWYU pragma: begin_exports
+
+// In at least two known scenarios when using GCC with libc++:
+//  * GCC 4.8 targeting ARMv7 with NEON
+//  * GCC 4.9 targeting ARMv8 64 bit
+// we need to typedef float float32_t (or include <arm_neon.h> which does that)
+// before #including <memory>. This makes no sense.  I'm not very interested in
+// understanding why... these are old, bizarre platform configuration that we
+// should just let die.
+#include <ciso646>  // Include something innocuous to define _LIBCPP_VERISON if it's libc++.
+#if defined(__GNUC__) && __GNUC__ == 4 \
+ && ((defined(SK_CPU_ARM32) && defined(SK_ARM_HAS_NEON)) || defined(SK_CPU_ARM64)) \
+ && defined(_LIBCPP_VERSION)
+    typedef float float32_t;
+    #include <memory>
+#endif
+
 #include "SkPreConfig.h"
 #include "SkUserConfig.h"
 #include "SkPostConfig.h"