Shader Line Annotation

[douira]

• add line directive insertion to ShaderParser,
• use assigned source ids to remap the sources in shader compilation logs,
• print merged shader sources to the log file in dev environments

Fixes #2680

[douira]

Please test if the included regex of the form \d+:\d+: works for the shader compilation logs produced by other drivers. If not, I'll adjust the regex to also match those. Also please test that the line numbers produced in the errors actually correspond to the line numbers in the source files, to make sure the drivers aren't interpreting the line directive differently.

[douira]

Removed remapping code, should be good to go now.