Add Emacs mode for .pipe files and to run GLSL through llpc

[JanRehders-AMD]

Some utilities to work with llpc.

• Major mode for .pipe files / llpc output
  • Highlight sections
  • imenu support to navigate to sections and passes
  • simple visualization of live ranges
• Compile GLSL shaders using llpc and show output in gpuopen-pipe-mode

[amdvlk-admin]

Test summary for commit bc77a1bffe2876facfc0004c213b7c7651ce7602

CTS tests (Failed: 0/143002)

• Built with version 1.3.5.2.RC
Ubuntu navi3x, Srdcvk
• Passed: 36386/71257 (51.1%)
• Failed: 0/71257 (0.0%)
• Not Supported: 34871/71257 (48.9%)
• Warnings: 0/71257 (0.0%)
Ubuntu navi2x, Srdcvk
• Passed: 36464/71745 (50.8%)
• Failed: 0/71745 (0.0%)
• Not Supported: 35281/71745 (49.2%)
• Warnings: 0/71745 (0.0%)