wrappers: Use clang config files for defaults

This makes these defaults more easy to get picked up in various
use cases, when not directly executing a compiler.

Dockerfile.dev

@@ -37,7 +37,7 @@ RUN ./strip-llvm.sh $TOOLCHAIN_PREFIX
 ARG TOOLCHAIN_ARCHS="i686 x86_64 armv7 aarch64"
 
 # Install the usual $TUPLE-clang binaries
-COPY wrappers/*.sh wrappers/*.c wrappers/*.h ./wrappers/
+COPY wrappers/*.sh wrappers/*.c wrappers/*.h wrappers/*.cfg ./wrappers/
 COPY install-wrappers.sh ./
 RUN ./install-wrappers.sh $TOOLCHAIN_PREFIX