[canvaskit] Disable dynamic execution

This required an update to emscripten, due to there being
a few bug fixes regarding the non-dynamic code and the
Closure compiler/minifier.

Change-Id: Icc922bd98cdd52a6923a9367da3747dac2b897b3
Bug: skia:12795
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/492916
Reviewed-by: Nathaniel Nifong <nifong@google.com>
22 files changed