dev-libs/xdna-driver: build against eselect-ed kernel, not booted one

This fixes build, when active kernel is Clang-built and ebuild uses
GCC-built one (and vice versa).

Signed-off-by: Sv. Lockal <lockalsash@gmail.com>

dev-libs/xdna-driver/files/xdna-driver-2.21.75-try-compile-config.patch

@@ -0,0 +1,18 @@
+Build using the configuration of the chosen kernel, not /proc/config.gz
+
+Upstream PR: https://github.com/amd/xdna-driver/pull/1285
+--- a/src/driver/tools/configure_kernel.sh
++++ b/src/driver/tools/configure_kernel.sh
+@@ -67,7 +67,11 @@ try_compile() {
+     conftest_c="$tmpdir/conftest.c"
+     conftest_mk="$tmpdir/Makefile"
+     USE_LLVM=""
+-    if [ -e /proc/config.gz ]; then
++    if [ -e "${KERNEL_SRC}/.config" ]; then
++        if grep -q "CONFIG_CC_IS_CLANG=y" "${KERNEL_SRC}/.config" 2>/dev/null; then
++            USE_LLVM="LLVM=1"
++        fi
++    elif [ -e /proc/config.gz ]; then
+         if zgrep -q "CONFIG_CC_IS_CLANG=y" /proc/config.gz 2>/dev/null; then
+             USE_LLVM="LLVM=1"
+         fi

dev-libs/xdna-driver/xdna-driver-2.21.75-r1.ebuild

@@ -119,6 +119,7 @@ src_prepare() {
 
 	pushd "${WORKDIR}/${P}" || die
 	eapply "${FILESDIR}/${PN}-2.21.75-llvm-support.patch"
+	eapply "${FILESDIR}/${PN}-2.21.75-try-compile-config.patch"
 	popd || die
 
 	default

dev-libs/xdna-driver/xdna-driver-999999.ebuild

@@ -119,6 +119,11 @@ src_unpack() {
 
 src_prepare() {
 	sed -e "s/-Werror//" -i Kbuild || die
+
+	pushd "${WORKDIR}/${P}" || die
+	eapply "${FILESDIR}/${PN}-2.21.75-try-compile-config.patch"
+	popd || die
+
 	default
 }