Makefile: restrict Rust unstable features for kernel modules

Suggested-by: bjorn3 <[email protected]>
Signed-off-by: Miguel Ojeda <[email protected]>

Author: ojeda

scripts/Makefile.build

@@ -300,6 +300,7 @@ quiet_cmd_rustc_o_rs = $(RUSTC_OR_CLIPPY_QUIET) $(quiet_modtag) $@
       cmd_rustc_o_rs = \
 	RUST_MODFILE=$(modfile) \
 	$(RUSTC_OR_CLIPPY) $(rustc_flags) $(rustc_cross_flags) \
+		-Zallow-features=allocator_api,bench_black_box,concat_idents,global_asm,try_reserve \
 		--extern alloc --extern kernel \
 		--crate-type rlib --out-dir $(obj) -L $(objtree)/rust/ \
 		--crate-name $(patsubst %.o,%,$(notdir $@)) $<; \