Rolling 4 dependencies

Roll third_party/SPIRV-Tools/ 2e1d208ed..c8590c18b (2 commits)

2e1d208ed9..c8590c18bd

$ git log 2e1d208ed..c8590c18b --date=short --no-merges --format='%ad %ae %s'
2020-05-06 jaebaek Preserve debug info for wrap-opkill (#3331)
2020-05-05 jbolz Validate ShaderCallKHR memory scope (#3332)

Roll third_party/shaderc/ 15a66d72f..6b4f6313e (3 commits)

15a66d72f3..6b4f6313ed

$ git log 15a66d72f..6b4f6313e --date=short --no-merges --format='%ad %ae %s'
2020-05-11 chinmaygarde Only add -fPIC if supported by the compiler. (#1061)
2020-05-06 rharrison Remove Singleton pattern around access to glslang (#1059)
2020-05-05 rharrison Add .NET bindings to README.md (#1060)

Roll third_party/spirv-cross/ 92f7d36c7..d638d2df9 (4 commits)

92f7d36c72..d638d2df9c

$ git log 92f7d36c7..d638d2df9 --date=short --no-merges --format='%ad %ae %s'
2020-05-08 post Support gl_InstanceID in RT shaders.
2020-05-06 post MSL: Avoid packed arrays in more cases.
2020-05-06 post Add missing reference files from PR merge.
2020-05-06 lehoangq Fix #1359: MSL: If the packed type is scalar, don't emit "pack_" prefix.

Roll third_party/tint/ 1f1f08f94..0bbf1e746 (6 commits)

https://dawn.googlesource.com/tint/+log/1f1f08f94a11..0bbf1e746093

$ git log 1f1f08f94..0bbf1e746 --date=short --no-merges --format='%ad %ae %s'
2020-05-11 rharrison Small fix for BUILD.gn
2020-05-08 dneto Rolling 6 dependencies
2020-05-07 dneto [spirv-reader] Find if-selection internal headers
2020-05-07 dneto [spirv-reader] Rename Edge::kToMerge to kIfBreak
2020-05-07 dneto [spirv-reader] Classify kSwitchBreak from deep in control flow
2020-05-07 dsinclair Rename brace and bracket to match spec

Created with:
  roll-dep third_party/SPIRV-Tools third_party/glslang third_party/shaderc third_party/spirv-cross third_party/spirv-headers third_party/tint

Change-Id: I7ad5ec308574599138a4297b8b4dd55c215bbf99
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/21520
Reviewed-by: Ryan Harrison <rharrison@chromium.org>
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Commit-Queue: Ryan Harrison <rharrison@chromium.org>

DEPS

@@ -61,13 +61,13 @@ deps = {
 
   # SPIRV-Cross
   'third_party/spirv-cross': {
-    'url': '{chromium_git}/external/github.com/KhronosGroup/SPIRV-Cross@92f7d36c72bc3cdbcc4aeff3534d096866013c0c',
+    'url': '{chromium_git}/external/github.com/KhronosGroup/SPIRV-Cross@d638d2df9c8c4a862e0af829cf49cc6dcbb235a2',
     'condition': 'dawn_standalone',
   },
 
   # SPIRV compiler dependencies: SPIRV-Tools, SPIRV-headers, glslang and shaderc
   'third_party/SPIRV-Tools': {
-    'url': '{chromium_git}/external/github.com/KhronosGroup/SPIRV-Tools@2e1d208ed9deab9048a00e60bb891d5e12a8332e',
+    'url': '{chromium_git}/external/github.com/KhronosGroup/SPIRV-Tools@c8590c18bd0c70dcd1caa7d43c5f2d020439b012',
     'condition': 'dawn_standalone',
   },
   'third_party/spirv-headers': {
@@ -79,13 +79,13 @@ deps = {
     'condition': 'dawn_standalone',
   },
   'third_party/shaderc': {
-    'url': '{chromium_git}/external/github.com/google/shaderc@15a66d72f33a099ec65e0fd37cf14548ed1d2bdb',
+    'url': '{chromium_git}/external/github.com/google/shaderc@6b4f6313ed8c87063e8c48482e1e365531d31da5',
     'condition': 'dawn_standalone',
   },
 
   # WGSL support
   'third_party/tint': {
-    'url': '{dawn_git}/tint@1f1f08f94a11f470a4551896df9f610b71876924',
+    'url': '{dawn_git}/tint@0bbf1e7460936422db9207a73cf987d510a8ae15',
     'condition': 'dawn_standalone',
   },