ports: Add llvm port

This can be compiled before mesa to make mesa use llvmpipe instead of
softpipe. llvmpipe is at least 10x faster :D

ports/llvm/build.sh

@@ -0,0 +1,34 @@
+#!/bin/bash ../install.sh
+
+NAME='llvm'
+VERSION='20.1.8'
+DOWNLOAD_URL="https://github.com/llvm/llvm-project/releases/download/llvmorg-$VERSION/llvm-project-$VERSION.src.tar.xz#6898f963c8e938981e6c4a302e83ec5beb4630147c7311183cf61069af16333d"
+TAR_CONTENT="llvm-project-$VERSION.src"
+DEPENDENCIES=('zlib' 'zstd')
+
+configure() {
+	unset CC CXX LD
+
+	$BANAN_CMAKE -B build -S llvm -G Ninja \
+		--toolchain="$BANAN_TOOLCHAIN_DIR/Toolchain.txt" \
+		-DCMAKE_BUILD_TYPE=Release \
+		-DCMAKE_INSTALL_PREFIX=/usr \
+		-DLLVM_ENABLE_PROJECTS= \
+		-DLLVM_ENABLE_RTTI=ON \
+		-DLLVM_TARGETS_TO_BUILD=X86 \
+		-DLLVM_INCLUDE_BENCHMARKS=OFF \
+		-DLLVM_INCLUDE_TESTS=OFF \
+		-DLLVM_HOST_TRIPLE=x86_64-pc-banan_os \
+		-DLLVM_PARALLEL_LINK_JOBS=1 \
+		 || exit 1
+}
+
+build() {
+	$BANAN_CMAKE --build build || exit 1
+}
+
+install() {
+	# This port only contains llvm libraries used optionally by
+	# mesa port. There is no need to install and fill the disk :D
+	:
+}