Stop building (empty) Skia AVX and SSSE3 opts files

This is the same as https://crrev.com/1183620

Bug: b/40045066
Change-Id: Ic34d7def87ed415ad79091d4685417710bad1617
Reviewed-on: https://pdfium-review.googlesource.com/c/pdfium/+/111271
Reviewed-by: Lei Zhang <thestig@chromium.org>
Commit-Queue: Lei Zhang <thestig@chromium.org>

skia/BUILD.gn

diff --git a/skia/BUILD.gn b/skia/BUILD.gn
index f9d1bf8..e2b7a2c 100644
--- a/skia/BUILD.gn
+++ b/skia/BUILD.gn
@@ -422,26 +422,6 @@
 
 # Bits that involve special vector-y hardware.
 if (current_cpu == "x86" || current_cpu == "x64") {
-  skia_source_set("skia_opts_sse3") {
-    sources = skia_opts.ssse3_sources
-    if (!is_win || is_clang) {
-      cflags = [ "-mssse3" ]
-    }
-    if (is_win) {
-      defines = [ "SK_CPU_SSE_LEVEL=31" ]
-    }
-    visibility = [ ":skia_opts" ]
-  }
-  skia_source_set("skia_opts_avx") {
-    sources = skia_opts.avx_sources
-    if (!is_win) {
-      cflags = [ "-mavx" ]
-    }
-    if (is_win) {
-      cflags = [ "/arch:AVX" ]
-    }
-    visibility = [ ":skia_opts" ]
-  }
   skia_source_set("skia_opts_hsw") {
     sources = skia_opts.hsw_sources
     if (!is_win) {
@@ -465,11 +445,7 @@
   defines = []
 
   if (current_cpu == "x86" || current_cpu == "x64") {
-    deps = [
-      ":skia_opts_avx",
-      ":skia_opts_hsw",
-      ":skia_opts_sse3",
-    ]
+    deps = [ ":skia_opts_hsw" ]
   } else if (current_cpu == "arm") {
     # The assembly uses the frame pointer register (r7 in Thumb/r11 in
     # ARM), the compiler doesn't like that.