Roll SwiftShader from b21967ee088b to 3c9e2a377a64 (4 revisions)

https://swiftshader.googlesource.com/SwiftShader.git/+log/b21967ee088b..3c9e2a377a64

2022-03-09 capn@google.com Pass the RelaxedPrecision decoration value to all affected instructions
2022-03-09 capn@google.com Support specifying math precision through a template argument
2022-03-09 capn@google.com Improve exp2 accuracy through weight adjustment
2022-03-09 swiftshader.regress@gmail.com Regres: Update test lists @ fc40ddd2

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

To file a bug in SwiftShader: https://bugs.chromium.org/p/swiftshader/issues/entry
To file a bug in Dawn: https://bugs.chromium.org/p/dawn/issues/entry

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/main/autoroll/README.md

Bug: None
Tbr: lokokung@google.com
Change-Id: I61aab05e2aa5eb60392d910b94c9002561fd245c
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/83140
Bot-Commit: Dawn Autoroller <dawn-autoroll@skia-public.iam.gserviceaccount.com>
Commit-Queue: Dawn Autoroller <dawn-autoroll@skia-public.iam.gserviceaccount.com>

DEPS

@@ -133,7 +133,7 @@ deps = {
   },
 
   'third_party/swiftshader': {
-    'url': '{swiftshader_git}/SwiftShader@b21967ee088b1fc420c1856389a8d739126479eb',
+    'url': '{swiftshader_git}/SwiftShader@3c9e2a377a645806e91723bda65e7236b3a15a00',
     'condition': 'dawn_standalone',
   },