Fix fuzzer-discovered error with sk_FragColor.
This built-in variable scanner would look for `sk_FragColor` or
`sk_Clockwise` in the symbol table and attempt to add them to your
program. However, if the user code had defined a symbol with this
name, there was nothing stopping the code from finding that user-
declared symbol instead. Now we explicitly only look in the built-in
symbol tables.
Change-Id: I970e58c96cd9cacdf48318d3ebb88560bbaa60fc
Bug: oss-fuzz:52603
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/595116
Auto-Submit: John Stiles <johnstiles@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: John Stiles <johnstiles@google.com>
8 files changed