libstd-rs: Move source directory to library/test

Building libstd-rs from library/std omits proc_macro from the sysroot.
Using library/test causes that to be installed which then allows cargo
to build (meta-rust/meta-rust#266)

(From OE-Core rev: 62527d5dadb79c70731e1dfd7b1f71495c78b267)

Signed-off-by: Alex Kiernan <[email protected]>
Signed-off-by: Alexandre Belloni <[email protected]>

Author: akiernan

meta/recipes-devtools/rust/libstd-rs_1.66.0.bb

@@ -6,8 +6,10 @@ LIC_FILES_CHKSUM = "file://../../COPYRIGHT;md5=92289ed52a60b63ab715612ad2915603"
 
 require rust-source.inc
 
-# libstd moved from src/libstd to library/std in 1.47+
-S = "${RUSTSRC}/library/std"
+# Building with library/std omits proc_macro from the sysroot. Using
+# library/test causes that to be installed which then allows cargo to
+# build (https://github.com/meta-rust/meta-rust/issues/266)
+S = "${RUSTSRC}/library/test"
 
 RUSTLIB_DEP = ""
 inherit cargo