glcpp: Exhaustively test all legal characters in GLSL

glcpp: Exhaustively test all legal characters in GLSL

Here, each legal character (as defined by GLSL Language Specification version
4.30.6, section 3.1) appears at least once in the input file. Obviously,
characters with special meaning (like '#' and '\') aren't treated exhaustively
with respect to all their possible uses. We have many other tests for that.

Here, we're simply ensuring that the test suite sees every legal character at
least once.

v2 (by Ken): Fix expectations, move to src/compiler, renumber tests.

   Carl's .expected:            Updated .expected:

   ..                           ..

   . .                          . .
   . .                          . .
   . .                          . .
   . .                          . .
   .                            ..
   .                            .
   .                            .
   .

(For some reason, the original test expected ".." to produce two lines.
glcpp, cpp, and mcpp all follow my updated behavior, so I believe it to
be correct.)

Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>