intel/compiler: add ability to override shader's assembly
When dumping shader's assembly with INTEL_DEBUG=vs,tcs,...
sha1 of the resulting assembly is also printed, having environment
variable INTEL_SHADER_ASM_READ_PATH
present driver will try to
load a "%sha1%.bin"
file from the path and substitute current
assembly with the one from the file.
The file with the assembly could be generated e.g. with:
./i965_asm --gen=kbl --type=bin test.txt -o 8a6b2ec7dbcf81f962a190408cb47931d20cc148.bin
The main current limitation is that one should be careful with jip offsets when changing the assembly especially with the instruction compaction (better use 'nocompact' debug option).