updated spirv-tools to latest version

Bug: skia:
Change-Id: I6a6ee1a3d7e63981e6e9c45cf2672060e31a6213
Reviewed-on: https://skia-review.googlesource.com/25020
Reviewed-by: Greg Daniel <egdaniel@google.com>
Commit-Queue: Ethan Nicholas <ethannicholas@google.com>
diff --git a/DEPS b/DEPS
index 3437fcc..6e25126 100644
--- a/DEPS
+++ b/DEPS
@@ -17,8 +17,8 @@
   "third_party/externals/piex"          : "https://android.googlesource.com/platform/external/piex.git@8f540f64b6c170a16fb7e6e52d61819705c1522a",
   "third_party/externals/sdl"           : "https://skia.googlesource.com/third_party/sdl@5d7cfcca344034aff9327f77fc181ae3754e7a90",
   "third_party/externals/sfntly"        : "https://chromium.googlesource.com/external/github.com/googlei18n/sfntly.git@b18b09b6114b9b7fe6fc2f96d8b15e8a72f66916",
-  "third_party/externals/spirv-headers" : "https://github.com/KhronosGroup/SPIRV-Headers.git@2d6ba39368a781edd82eff5df2b6bc614e892329",
-  "third_party/externals/spirv-tools"   : "https://github.com/KhronosGroup/SPIRV-Tools.git@1fb8c37b5718118b49eec59dc383cfa3f98643c0",
+  "third_party/externals/spirv-headers" : "https://github.com/KhronosGroup/SPIRV-Headers.git@661ad91124e6af2272afd00f804d8aa276e17107",
+  "third_party/externals/spirv-tools"   : "https://github.com/KhronosGroup/SPIRV-Tools.git@e9e4393b1c5aad7553c05782acefbe32b42644bd",
  #"third_party/externals/v8"            : "https://chromium.googlesource.com/v8/v8.git@5f1ae66d5634e43563b2d25ea652dfb94c31a3b4",
   "third_party/externals/zlib"          : "https://chromium.googlesource.com/chromium/src/third_party/zlib@4576304a4b9835aa8646c9735b079e1d96858633",
 }