Rolling 3 dependencies

Roll third_party/SPIRV-Tools/ fd773eb50..e95fbfb1f (9 commits)

https://chromium.googlesource.com/external/github.com/KhronosGroup/SPIRV-Tools/+log/fd773eb50d62..e95fbfb1f509

$ git log fd773eb50..e95fbfb1f --date=short --no-merges --format='%ad %ae %s'
2020-04-02 afdx spirv-fuzz: Transformation to add OpConstantNull (#3273)
2020-04-02 afdx spirv-fuzz: Handle isomorphic types property in composite construction (#3262)
2020-04-02 afdx spirv-fuzz: Limit adding of new variables to 'basic' types (#3257)
2020-04-02 afdx spirv-fuzz: Only replace regular ids with synonyms (#3255)
2020-04-02 afdx spirv-fuzz: Introduce TransformationContext (#3272)
2020-04-02 afdx spirv-fuzz: Add validator options (#3254)
2020-04-02 alanbaker Update dominates to check for null nodes (#3271)
2020-04-01 alanbaker Set wrapped kill basic block's parent (#3269)
2020-03-31 caio.oliveira Validate Buffer and BufferBlock apply only to struct types (#3259)

Roll third_party/glslang/ 08c02ced7..b5757b950 (5 commits)

https://chromium.googlesource.com/external/github.com/KhronosGroup/glslang/+log/08c02ced798a..b5757b95005b

$ git log 08c02ced7..b5757b950 --date=short --no-merges --format='%ad %ae %s'
2020-04-03 rharrison Remove extra semicolons (#2170)
2020-04-02 mbechard Shader interface matching rework to fix #2136 (#2156)
2020-04-01 cepheus Build warning: Fix #2167: Remove nested reuse of 'unreachable'.
2020-03-31 cepheus Bump revision.
2020-03-30 alele Error assigns to objects of rayQueryEXT type.

Roll third_party/spirv-cross/ 9b3c5e12b..6637610b1 (7 commits)

https://chromium.googlesource.com/external/github.com/KhronosGroup/SPIRV-Cross/+log/9b3c5e12be12..6637610b16aa

$ git log 9b3c5e12b..6637610b1 --date=short --no-merges --format='%ad %ae %s'
2020-04-03 post Expose a query if samplers or images are comparison resources.
2020-04-03 post Do not add NonWritable/NonReadable decorations for regular images.
2020-04-03 post MSL: Deal with cases where builtin is implicitly needed, declared, but unused.
2020-04-03 post HLSL: Add support for treating NonWritable UAV texture as SRV instead.
2020-04-03 troughton MSL: mark BuiltInFragCoord as implicitly used for subpass reads
2020-03-31 post MSL: Fix access chain for deep struct hierarchy on array of buffers.
2020-03-30 dsinclair Roll GLSLang, SPIRV-Tools and SPIRV-Headers

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

Change-Id: Ia60a082e6d8b7bc954fedeb444cb5c91bf252f17
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/18880
Reviewed-by: Ryan Harrison <rharrison@chromium.org>
Commit-Queue: Ryan Harrison <rharrison@chromium.org>
diff --git a/DEPS b/DEPS
index 1565abd..2089e3e 100644
--- a/DEPS
+++ b/DEPS
@@ -51,13 +51,13 @@
 
   # SPIRV-Cross
   'third_party/spirv-cross': {
-    'url': '{chromium_git}/external/github.com/KhronosGroup/SPIRV-Cross@9b3c5e12be12c55533f3bd3ab9cc617ec0f393d8',
+    'url': '{chromium_git}/external/github.com/KhronosGroup/SPIRV-Cross@6637610b16aacfe43c77ad4060da62008a83cd12',
     '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@fd773eb50d628c1981338addc093df879757c2cf',
+    'url': '{chromium_git}/external/github.com/KhronosGroup/SPIRV-Tools@e95fbfb1f509ad7a7fdfb72ac35fe412d72fc4a4',
     'condition': 'dawn_standalone',
   },
   'third_party/spirv-headers': {
@@ -65,7 +65,7 @@
     'condition': 'dawn_standalone',
   },
   'third_party/glslang': {
-    'url': '{chromium_git}/external/github.com/KhronosGroup/glslang@08c02ced798afe357349d0e422cd474aa1eb0c79',
+    'url': '{chromium_git}/external/github.com/KhronosGroup/glslang@b5757b95005bbf6b0287096c5b708c5e25645311',
     'condition': 'dawn_standalone',
   },
   'third_party/shaderc': {