Add size checks for glBufferData and glBufferSubData

Without the size checks it's possible for calls to glBufferData
and glBufferSubData to read off the end of the Buffer object's
data, which can cause page faults.

Fix end-of-line characters for the "spec" files. (That's why
every line of these files is changed.)

Enhance our code emitter to properly handle bounds checks for
possibly-null pointers.