Specifically, make GLSL link error messages more specific and output
only information relevant to the error.
Also change type printing to more closely reflect GLSL syntax. This
is the default for link error messages, but must me enabled with the
new option --enhanced-msgs for compilation error messages.
Also with --enhanced-msgs, only emit one error message per source
line.
Prior to this change, OES_primitive_bounding_box and EXT_primitive_bounding_box were both recognised as extensions, but only the name gl_BoundingBoxOES could be used. However the EXT version uses the name gl_BoundingBoxEXT instead. In addition, since GLES 3.2, the extension has been included in the core standard and the name gl_BoundingBox may be used instead. This change aims to make both extensions and the 3.2 core version all work.
