This is a sample program that can be used to compile a shader and
inspect the intermediate tree or the output from the shader translator.
This change adds support for the recently added desktop GLSL inputs as
well as the ability to produce Vulkan GLSL output.

Bug: angleproject:3453
Change-Id: I1f378e8d84b74636d6a47ce1aaff5f1f55f5bbb3
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/1784881Reviewed-by: Cody Northrop <cnorthrop@google.com>
Reviewed-by: Geoff Lang <geofflang@chromium.org>
Commit-Queue: Shahbaz Youssefi <syoussefi@chromium.org>