Roll third_party/tint/ af5df70c7..3f3483be1 (2 commits)

https://dawn.googlesource.com/tint/+log/af5df70c7bd0..3f3483be14b1

$ git log af5df70c7..3f3483be1 --date=short --no-merges --format='%ad %ae %s'
2020-06-10 rharrison Fix BUILD.gn based builds
2020-06-09 dneto [spirv-reader] Avoid emitting empty elses

Created with:
  roll-dep third_party/tint

Change-Id: I5b67f39fbfaa0609dfc835a349983a42a028d581
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/23121
Reviewed-by: Ryan Harrison <rharrison@chromium.org>
Commit-Queue: Ryan Harrison <rharrison@chromium.org>
diff --git a/DEPS b/DEPS
index fced238..f60b63d 100644
--- a/DEPS
+++ b/DEPS
@@ -85,7 +85,7 @@
 
   # WGSL support
   'third_party/tint': {
-    'url': '{dawn_git}/tint@af5df70c7bd0097dbde897afce2982ff2b42c531',
+    'url': '{dawn_git}/tint@3f3483be14b157fce49d324a8b035cecde10697a',
     'condition': 'dawn_standalone',
   },