PKGBUILD: Enable QR Code Panic for GCC compiled kernels

[ptr1337]

This does enable the QR Code Panic Screen for GCC compiled kernels until LLVM (Thin) LTO does support it.

Not applied to all kernels yes, will do this after review

[Copilot]

Pull Request Overview

This PR adds support for enabling the QR Code Panic Screen for GCC-compiled kernels until LLVM (Thin) LTO supports it. Key changes include:

• Adding a conditional block in the prepare() function to enable QR Code Panic via scripts/config when LLVM LTO is not used.
• Installing Rust files in the _package-headers() function when compiling with GCC.

[Copilot]

[nitpick] The scripts/config command that follows spans several options, which makes it difficult to read. Consider refactoring it by either splitting it into multiple lines (with proper line continuations) or assigning the options to a variable for improved maintainability.

Suggested change

	scripts/config -e RUST_IS_AVAILABLE -e CONFIG_RUST -e RUST_FW_LOADER_ABSTRACTIONS -d CONFIG_BLK_DEV_RUST_NULL --set-str DRM_PANIC_SCREEN qr-code \
	-e DRM_PANIC_SCREEN_QR_CODE --set-str DRM_PANIC_SCREEN_QR_CODE_URL https://panic.archlinux.org/panic_report# --set-str DRM_PANIC_SCREEN_QR_VERSION 40
	config_options=(
	"-e RUST_IS_AVAILABLE"
	"-e CONFIG_RUST"
	"-e RUST_FW_LOADER_ABSTRACTIONS"
	"-d CONFIG_BLK_DEV_RUST_NULL"
	"--set-str DRM_PANIC_SCREEN qr-code"
	"-e DRM_PANIC_SCREEN_QR_CODE"
	"--set-str DRM_PANIC_SCREEN_QR_CODE_URL https://panic.archlinux.org/panic_report#"
	"--set-str DRM_PANIC_SCREEN_QR_VERSION 40"
	)
	scripts/config "${config_options[@]}"

[Copilot]

Before installing the Rust files, ensure the target directory ('$builddir/rust') exists (e.g., by creating it with mkdir -p) to avoid potential install errors.

Suggested change

	echo "Installing Rust files..."
	echo "Installing Rust files..."
	mkdir -p "$builddir/rust"

[1Naim]

Suggested change

	scripts/config -e RUST_IS_AVAILABLE -e CONFIG_RUST -e RUST_FW_LOADER_ABSTRACTIONS -d CONFIG_BLK_DEV_RUST_NULL --set-str DRM_PANIC_SCREEN qr-code \
	scripts/config -e RUST -e RUST_FW_LOADER_ABSTRACTIONS -d BLK_DEV_RUST_NULL --set-str DRM_PANIC_SCREEN qr-code \

I believe RUST_IS_AVAILABLE is automatically flipped if rustc is detected, so we don't need to explicitly enable it here.