build: make sure LLVM is exactly correct
build: make sure LLVM is exactly correct

 * check the version to be the correct major version
 * ensure that it has all the default targets enabled

raulgrell/zig,raulgrell/zig,raulgrell/zig,andrewrk/zig,zig-lang/zig,raulgrell/zig,raulgrell/zig,andrewrk/zig,zig-lang/zig,zig-lang/zig