[MIPS] Further opengl support for mips64 and mipsr6

Combines 4 patches by Dragoslav and Douglas:

Use t9 to hold the address of the called function.
Add support for gl binding.
Fix inline assembly code to be R6 compatible.
Fix some more inline assembly code to be R6 compatible.

Change-Id: I0b899813790b2ba4ca538bb21692014cc1933f66
3 files changed