Roll SPIRV-Tools from 7221ccf85e26 to 680c77fa6c81 (2 revisions)

https://chromium.googlesource.com/external/github.com/KhronosGroup/SPIRV-Tools.git/+log/7221ccf85e26..680c77fa6c81

If this roll has caused a breakage, revert this CL and stop the roller
using the controls here:
https://autoroll.skia.org/r/spirv-tools-angle-autoroll
Please CC jonahr@google.com on the revert to ensure that a human
is aware of the problem.

To report a problem with the AutoRoller itself, please file a bug:
https://bugs.chromium.org/p/skia/issues/entry?template=Autoroller+Bug

Documentation for the AutoRoller is here:
https://skia.googlesource.com/buildbot/+doc/master/autoroll/README.md

Bug: None
Tbr: jonahr@google.com
Change-Id: Ibccb8cb205986112774a2ba1c7489edf3662ee10
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2304358
Reviewed-by: angle-autoroll <angle-autoroll@skia-public.iam.gserviceaccount.com>
Commit-Queue: angle-autoroll <angle-autoroll@skia-public.iam.gserviceaccount.com>
diff --git a/DEPS b/DEPS
index 5052393..816c808 100644
--- a/DEPS
+++ b/DEPS
@@ -57,7 +57,7 @@
   'spirv_headers_revision': 'ac638f1815425403e946d0ab78bac71d2bdbf3be',
 
   # Current revision of SPIRV-Tools for Vulkan.
-  'spirv_tools_revision': '7221ccf85e26a29459729b3d296b71346c538a94',
+  'spirv_tools_revision': '680c77fa6c81ba03d19b3315d1cad116fc4e6da2',
 
   # Current revision of Khronos Vulkan-Headers.
   'vulkan_headers_revision': '858b13a1220a20d2bed98779b99d38d797d070e5',