Make indentation in all.tests PEP8-compliant.

Re-indented the file using the script
https://github.com/stereotype441/mesa-tools/blob/master/fix-indentation.py.
This is the same script I used for
http://cgit.freedesktop.org/mesa/mesa/commit/?id=99802519b47983be8301a0283f2946a44a9656a5
("glapi: Reformat python code generation scripts to use 4-space
indentation.")
util: Add piglit_build_simple_program_unlinked().
Make use of piglit_build_simple_program_unlinked() in some tests.
gs: Test that geometry shader inputs must be arrays.

v2: Additional tests.
gs: Test that geometry shader input declaration rules don't apply to outputs.
gs: Test EndPrimitive() functionality.
!UPSTREAM: Test core GS inputs on GLSL 1.50

TODO:
- Make this work.