Add neon and crc32 sources for aarch64

BUILD.gn

Index: BUILD.gn
diff --git a/BUILD.gn b/BUILD.gn
index e0ed2a6f80d2d1d406f1f296c4bf79f6c2537b4d..eb2aa9a07adb715c3ba1ef15901ef047c743fdd9 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -167,6 +167,18 @@ opts("none") {
   cflags = []
 }
 
+opts("neon_sources") {

[mtklein, 2016/08/25 01:26:44]

Hmm.  It's gonna have to be a little more complicated than this.

opts("armv7") {
  enabled = target_cpu == "arm"
  sources = opts_gypi.armv7_sources
  cflags = []
}

opts("neon") {
  enabled = target_cpu == "arm"
  sources = opts_gypi.neon_sources
  cflags = [ "-mfpu=neon" ]
}

opts("arm64") {
  enabled = target_cpu == "arm64"
  sources = opts_gypi.arm64_sources
  cflags = []
}

opts("crc32") {
  enabled = target_cpu == "arm64"
  sources = opts_gypi.crc32_sources
  cflags = [ "-march=armv8-a+crc" ]
}

and the enabled bit for :none will need to change to
 enabled = !is_x86 && target_cpu != "arm" && target_cpu != "arm64"

[anmittal, 2016/08/25 03:03:58]

Done.

+  enabled = !is_x86
+  sources = opts_gypi.neon_sources
+  cflags = []
+}
+
+opts("crc32_sources") {
+  enabled = !is_x86
+  sources = opts_gypi.crc32_sources
+  cflags = []
+}
+
 opts("sse2") {
   enabled = is_x86
   sources = opts_gypi.sse2_sources
@@ -316,8 +328,10 @@ component("skia") {
 
   deps = [
     ":avx",
+    ":crc32_sources",
     ":gif",
     ":jpeg",
+    ":neon_sources",
     ":none",
     ":pdf",
     ":png",