Add support for casting ints and floats to bool.

These casts are implemented as `notEqual(x, 0)`.
This causes five additional tests to pass (58/190):

inliner/TernaryTestCanBeInlined.sksl
inliner/TernaryResultsCannotBeInlined.sksl
inliner/ShortCircuitEvaluationsCannotInlineRightHandSide.sksl
inliner/IfTestCanBeInlined.sksl
inliner/IfElseChainWithReturnsCanBeInlined.sksl

Change-Id: I6ad5442fdd4f3d5d9aaaa4b04db14ecc305465c7
Bug: skia:13676
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/625677
Commit-Queue: John Stiles <johnstiles@google.com>
Auto-Submit: John Stiles <johnstiles@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>
4 files changed