- Updated preprocessor code from Angle revision
  9fc8733187c02470a9eadb6d295348b6d37a2004
- Reran generate_parser.sh (flex 2.6.4, bison (GNU Bison) 3.0.4)
- Made a few trivial changes in src/OpenGL/compiler in order to
  adapt to the new preprocessor code.

Fixes all 24 failures in:
dEQP-GLES3.functional.shaders.preprocessor.*

Change-Id: I00d0b511d617ab81a0f57310174e1ba8bf7c22e5
Reviewed-on: https://swiftshader-review.googlesource.com/15109Tested-by: Alexis Hétu <sugoi@google.com>
Reviewed-by: Nicolas Capens <nicolascapens@google.com>