The following large tests have been split into smaller parts by instruction formats:
gfx7_asm_all.s
gfx8_asm_all.s
gfx9_asm_all.s
gfx10_asm_all.s
This change results in noticeable lit testing speedup.
For example, on a debug Windows build, split asm tests are run 3.5 times faster.
