shaderc: 2019.1 -> 2020.1

[jansol]

Motivation for this change

https://github.com/google/shaderc/blob/main/CHANGES

Adds support for more recent features such as the GL_KHR_ray_tracing extension.

Needs

• libplacebo <= 2.72.0 fails to build against this version of shaderc. Upstream has merged a fix, this PR is waiting for a new release to be tagged there.

Things done

• Tested using sandboxing (nix.useSandbox on NixOS, or option sandbox in nix.conf on non-NixOS linux)
• Built on platform(s)
  • NixOS
  • macOS
  • other Linux distributions
• Tested via one or more NixOS test(s) if existing and applicable for the change (look inside nixos/tests)
• Tested compilation of all pkgs that depend on this change using nix-shell -p nixpkgs-review --run "nixpkgs-review wip"
• Tested execution of all binary files (usually in ./result/bin/)
• Determined the impact on package closure size (by running nix path-info -S before and after)
• Ensured that relevant documentation is up to date
• Fits CONTRIBUTING.md.

[Ralith]

Thanks!

[danieldk]

With this bump, building libplacebo fails with:

  [42/44] Compiling C++ object 'src/25a6634@@placebo@sha/glsl_glslang.cc.o'K[Ken.c.o'
  FAILED: src/25a6634@@placebo@sha/glsl_glslang.cc.o 
  g++ -Isrc/25a6634@@placebo@sha -Isrc -I../src -I../src/include -I../src/include/dummy -I../subprojects/xtalloc/include -I../subprojects/bstr/include -I/nix/store/fhdih4qf2hj168r1q90jj7rf0087bhk9-lcms2-2.10-dev/include -I/nix/store/10h8jy0j0vrnvw5yf77v4nnggbwypfnz-vulkan-headers-1.2.131.1/include -I/nix/store/6anqhjcik07x9srlyh7aw03binyx9bkx-epoxy-1.5.4-dev/include -I/usr/include/glslang -I/nix/store/yymrc0m2mz1cd94bm0wnkmxr9kigh68j-libplacebo-2.72.0/include/glslang -fdiagnostics-color=always -pipe -D_FILE_OFFSET_BITS=64 -std=c++11 -Wundef -Wshadow -Wparentheses -Wpointer-arith -fvisibility=hidden -fPIC -pthread -MD -MQ 'src/25a6634@@placebo@sha/glsl_glslang.cc.o' -MF 'src/25a6634@@placebo@sha/glsl_glslang.cc.o.d' -o 'src/25a6634@@placebo@sha/glsl_glslang.cc.o' -c ../src/glsl/glslang.cc
  ../src/glsl/glslang.cc:226:1: error: cannot convert '<brace-enclosed initializer list>' to 'int' in initialization
    226 | };
        | ^

[jansol]

Looks like libplacebo already has a fix for that, but it has not been released yet: https://code.videolan.org/videolan/libplacebo/-/issues/100

[jonringer]

causes a regression in libplacebo

FAILED: src/25a6634@@placebo@sha/glsl_glslang.cc.o
g++ -Isrc/25a6634@@placebo@sha -Isrc -I../src -I../src/include -I../src/include/dummy -I../subprojects/xtalloc/include -I../subprojects/bstr/include -I/nix/store/81iy20n5rhvcm18ha289anygpgq5qyjc-lcms2-2.11-dev/include -I/nix/store/3gmgj9qc3wgbd96b394vamky3d0zzjjd-vulkan-headers-1.2.131.1/include -I/nix/store/psda85jw38cxzqp6fa59vrdipz67h6bk-epoxy-1.5.4-dev/include -I/usr/include/glslang -I/nix/store/crkinam09rw65x4nrjn2wirnfs9l1q51-libplacebo-2.72.0/include/glslang -fdiagnostics-color=always -pipe -D_FILE_OFFSET_BITS=64 -std=c++11 -Wundef -Wshadow -Wparentheses -Wpointer-arith -fvisibility=hidden -fPIC -pthread -MD -MQ 'src/25a6634@@placebo@sha/glsl_glslang.cc.o' -MF 'src/25a6634@@placebo@sha/glsl_glslang.cc.o.d' -o 'src/25a6634@@placebo@sha/glsl_glslang.cc.o' -c ../src/glsl/glslang.cc
../src/glsl/glslang.cc:226:1: error: cannot convert '<brace-enclosed initializer list>' to 'int' in initialization
  226 | };
      | ^

[jonringer]

I should really read the other comments closely... sorry xD

[SuperSandro2000]

This PR got superseded by #94049.

[doronbehar]

I should really read the other comments closely... sorry xD

I should too :/.

[jonringer]

sorry @jansol for not following back up with this