Fix assertion in inliner when makeSampler2D is used.

We can't create variables of opaque type, so we cannot inline functions
if they have an opaque argument that would need a scratch copy. This
solves an assertion when trying to inline a call that contains
`makeSampler2D(...)` in its argument list.

Bug: skia:13824
Change-Id: I7c92d192f5a283c96a064cac9b2542460a5ec702
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/726576
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: John Stiles <johnstiles@google.com>
Auto-Submit: John Stiles <johnstiles@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
6 files changed