Enable -Wextra-semi

Bug: b/40045194
Change-Id: I2c367b6aee2d4f292809cee8e90abd8bdbd0a34f
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/816716
Reviewed-by: Robert Phillips <robertphillips@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
26 files changed