Remove -mimplicit-it=always from skia asm flags.

This was added to work around skia issue 297, but that's been fixed for years.
clang's integrated assembler doesn't understand -mimplicit-it=, so as it's not
needed here, just remove it.

BUG=86592,skia:297,124610
R=piman@chromium.org

Review URL: https://codereview.chromium.org/463653002

Cr-Commit-Position: refs/heads/master@{#288830}
git-svn-id: svn://svn.chromium.org/chrome/trunk/src@288830 0039d316-1c4b-4281-b951-d872f2087c98

skia/BUILD.gn

@@ -629,13 +629,6 @@ source_set("skia_opts") {
           "//third_party/skia/src/opts/memset32_neon.S",
         ]
 
-        cflags += [
-          # The neon assembly contains conditional instructions which aren't
-          # enclosed in an IT block. The assembler complains without this
-          # option. See #86592.
-          "-Wa,-mimplicit-it=always",
-        ]
-
         # Root build config sets -mfpu=$arm_fpu, which we expect to be neon
         # when running this.
         if (!arm_use_neon) {

skia/skia_library_opts.gyp

@@ -66,13 +66,6 @@
         [ 'target_arch == "arm"', {
           'conditions': [
             [ 'arm_version >= 7 and (arm_neon == 1 or arm_neon_optional == 1)', {
-              'cflags': [
-                # The neon assembly contains conditional instructions which
-                # aren't enclosed in an IT block. The assembler complains
-                # without this option.
-                # See #86592.
-                '-Wa,-mimplicit-it=always',
-              ],
               'dependencies': [
                 'skia_opts_neon',
               ]