Replace obsolescent egrep with grep -E in lint script

Replace deprecated egrep command with the modern equivalent 'grep -E'
to eliminate warnings about egrep being obsolescent. This improves
the lint script output clarity without changing functionality.

Also add codegen-backend override to prevent cranelift conflicts
from parent directory configurations, ensuring rust-gpu builds
with the required LLVM backend.

Author: zmr-233

.cargo/config.toml

@@ -14,6 +14,10 @@ rustflags = [
     "-Zshare-generics=n", # =off is also an option, but you're going to increase binary size in doing so.
 ]
 
+# Override parent directory's cranelift backend setting for rust-gpu compatibility
+[profile.dev]
+codegen-backend = "llvm"
+
 [target.'cfg(all())']
 rustflags = [
     # FIXME(eddyb) update/review these lints.

.github/workflows/lint.sh

@@ -49,15 +49,15 @@ clippy_no_features examples/shaders/simplest-shader
 # which could be disastrous because env vars access can't be tracked by
 # `rustc`, unlike its CLI flags (which are integrated with incremental).
 if (
-    egrep -r '::\s*env|env\s*::' crates/rustc_codegen_spirv/src |
+    grep -E -r '::\s*env|env\s*::' crates/rustc_codegen_spirv/src |
     # HACK(eddyb) exclude the one place in `rustc_codegen_spirv`
     # needing access to an env var (only for codegen args `--help`).
-    egrep -v '^crates/rustc_codegen_spirv/src/codegen_cx/mod.rs:            let help_flag_comes_from_spirv_builder_env_var = std::env::var\(spirv_builder_env_var\)$' |
+    grep -E -v '^crates/rustc_codegen_spirv/src/codegen_cx/mod.rs:            let help_flag_comes_from_spirv_builder_env_var = std::env::var\(spirv_builder_env_var\)$' |
     # HACK(LegNeato) exclude logging. This mirrors `rustc` (`RUSTC_LOG`) and 
     #`rustdoc` (`RUSTDOC_LOG`).
     # There is not a risk of this being disastrous as it does not change the build settings.
-    egrep -v '^crates/rustc_codegen_spirv/src/lib.rs:.*(RUSTGPU_LOG|RUSTGPU_LOG_FORMAT|RUSTGPU_LOG_COLOR).*$' |
-    egrep -v '^crates/rustc_codegen_spirv/src/lib.rs:    use std::env::{self, VarError};$'
+    grep -E -v '^crates/rustc_codegen_spirv/src/lib.rs:.*(RUSTGPU_LOG|RUSTGPU_LOG_FORMAT|RUSTGPU_LOG_COLOR).*$' |
+    grep -E -v '^crates/rustc_codegen_spirv/src/lib.rs:    use std::env::{self, VarError};$'
 
 ); then
     echo '^^^'