This is a reland of c412688798
This CL lands the code changes but not the dm test, which is causing
link errors. Tests will be relanded as a separate CL, at
http://review.skia.org/400097
Original change's description:
> Reland "Implement statements and expressions in DSL C++ code generator."
>
> This is a reland of 16cbfb41df
>
> Tests now rely on `shaderDerivativeSupport` and `integerSupport` as
> proxies to indicate ES3 support. The SwitchStatement test has been
> adjusted to hopefully confuse fewer compilers.
>
> Original change's description:
> > Implement statements and expressions in DSL C++ code generator.
> >
> > This CL removes the bulk of the existing C++ code generator, especially
> > all the complex format-string assembly code. It has been replaced with
> > actual DSL code generation. Simple IR can now be successfully translated
> > to a working DSL fragment processor.
> >
> > This CL also adds a simple test harness which is patterned after the
> > existing SkSLTest; it renders a pixel, reads it back, and fails the test
> > if the result isn't solid green (RGBA=0101).
> >
> > This CL doesn't implement every feature. Some obvious gaps include:
> > - Sampling from children
> > - Uniforms/inputs of any kind
> > - Function calls of any kind
> >
> > Change-Id: Ib80c23fe1ba4453f7c3cb43b65f93c5ea0deb709
> > Bug: skia:11854
> > Reviewed-on: https://skia-review.googlesource.com/c/skia/+/396757
> > Reviewed-by: Ethan Nicholas <ethannicholas@google.com>
> > Reviewed-by: Brian Osman <brianosman@google.com>
> > Commit-Queue: John Stiles <johnstiles@google.com>
>
> Bug: skia:11854, skia:11891
> Change-Id: I91363e31f34611d15ae350b52d6fc459feeace9c
> Reviewed-on: https://skia-review.googlesource.com/c/skia/+/399076
> Auto-Submit: John Stiles <johnstiles@google.com>
> Commit-Queue: Ethan Nicholas <ethannicholas@google.com>
> Reviewed-by: Ethan Nicholas <ethannicholas@google.com>
Bug: skia:11854
Bug: skia:11891
Change-Id: Ib1f08256c84d1da2130e0b61356f72435dc0a5a8
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/399740
Reviewed-by: Ethan Nicholas <ethannicholas@google.com>
Commit-Queue: Ethan Nicholas <ethannicholas@google.com>
Commit-Queue: John Stiles <johnstiles@google.com>
Auto-Submit: John Stiles <johnstiles@google.com>
956802335d