Add improved regression test for oss-fuzz:36655.

Most of the code generated by the fuzzer is nonsense, but there is a
method to its madness. The crash is only triggered under specific
conditions:
- The runtime effect has enough helper functions to mostly fill up the
  call graph hash-map. It won't rehash until it gets close to capacity.
- There must be several calls to built-in functions, in order to add
  elements to the call graph to force a rehash.

The fuzzer-generated code manages to satisfy both these requirements.

Change-Id: I9a1d7535557fedd4e9bfece3930ac86ede291ffe
Bug: oss-fuzz:36655
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/437118
Auto-Submit: John Stiles <johnstiles@google.com>
Reviewed-by: Ethan Nicholas <ethannicholas@google.com>
Commit-Queue: John Stiles <johnstiles@google.com>
7 files changed