Disable SSE4 S32A_Opaque blit.

This code sometimes generates a build warning that bothers Chrome.

BUG=399842,skia:2906
R=reed@google.com, mtklein@google.com

Author: mtklein@chromium.org

Review URL: https://codereview.chromium.org/538463003
diff --git a/src/opts/SkBlitRow_opts_SSE4.h b/src/opts/SkBlitRow_opts_SSE4.h
index f202aa5..600e669 100644
--- a/src/opts/SkBlitRow_opts_SSE4.h
+++ b/src/opts/SkBlitRow_opts_SSE4.h
@@ -10,6 +10,8 @@
 
 #include "SkBlitRow.h"
 
+#ifdef CRBUG_399842_FIXED
+
 /* Check if we are able to build assembly code, GCC/AT&T syntax:
  *  1) Clang and GCC are generally OK.  OS X's old LLVM-GCC 4.2 can't handle it;
  *  2) We're intentionally not linking this in even when supported (Clang) on Windows;
@@ -25,5 +27,7 @@
 #define SK_ATT_ASM_SUPPORTED
 #endif
 
+#endif // CRBUG_399842_FIXED
+
 #endif
 
diff --git a/src/opts/SkBlitRow_opts_SSE4_asm.S b/src/opts/SkBlitRow_opts_SSE4_asm.S
index 417e517..0f52817 100644
--- a/src/opts/SkBlitRow_opts_SSE4_asm.S
+++ b/src/opts/SkBlitRow_opts_SSE4_asm.S
@@ -5,6 +5,8 @@
  * found in the LICENSE file.
  */
 
+#ifdef CRBUG_399842_FIXED
+
 #if defined(__clang__) || (defined(__GNUC__) && !defined(SK_BUILD_FOR_MAC))
 
 #define CFI_PUSH(REG) \
@@ -469,3 +471,5 @@
     .size S32A_Opaque_BlitRow32_SSE4_asm, .-S32A_Opaque_BlitRow32_SSE4_asm
 #endif
 #endif
+
+#endif // CRBUG_399842_FIXED
diff --git a/src/opts/SkBlitRow_opts_SSE4_x64_asm.S b/src/opts/SkBlitRow_opts_SSE4_x64_asm.S
index 41a147e..9a754a6 100644
--- a/src/opts/SkBlitRow_opts_SSE4_x64_asm.S
+++ b/src/opts/SkBlitRow_opts_SSE4_x64_asm.S
@@ -5,6 +5,8 @@
  * found in the LICENSE file.
  */
 
+#ifdef CRBUG_399842_FIXED
+
 #if defined(__clang__) || (defined(__GNUC__) && !defined(SK_BUILD_FOR_MAC))
 
 #define EXTRACT_ALPHA(var1, var2) \
@@ -466,3 +468,5 @@
 .LResultMergeMask:
     .long   0x00FF00FF, 0x00FF00FF, 0x00FF00FF, 0x00FF00FF
 #endif
+
+#endif // CRBUG_399842_FIXED