Include .rlib files in -dev package

[#119](#119) added the
feature to install examples and libraries by default if they exist. An
unintended consequence of that though was breaking existing builds when a .rlib
file was installed but then not included in the FILES directive.

To keep parity with meta-rust we'll start packaging .rlib files in the -dbg
package.

Signed-off-by: Nick Stevens <nick@bitcurry.com>

Author: nastevens

classes/cargo.bbclass

@@ -40,6 +40,8 @@ WRAPPER_DIR = "${WORKDIR}/wrappers"
 # Set the Cargo manifest path to the typical location
 CARGO_MANIFEST_PATH ?= "${S}/Cargo.toml"
 
+FILES:${PN}-dev += "${libdir}/*.rlib"
+
 CARGO_BUILD_FLAGS = "\
     --verbose \
     --manifest-path ${CARGO_MANIFEST_PATH} \