Improve performance of determineFinalTypes.

This function was originally responsible for about ~1% of compilation
time, almost entirely due to unnecessary vector allocation. The call to
`coercibleTypes` was copying the result every time due to a missing &,
and the `outParameterTypes` vector was not calling reserve before being
populated. Additionally, converted the out-parameter array to an
SkSTArray so that in the common case, we should not need to allocate at
all.

Change-Id: Iad085cf4ebc61d1ae1a92cc5f214272580ab0959
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/325862
Auto-Submit: John Stiles <johnstiles@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>
2 files changed