test duplicate features, that the last +/-lld on the CLI wins

Author: lqd

tests/run-make/rust-lld/Makefile

@@ -6,3 +6,7 @@ include ../tools.mk
 all:
 	RUSTC_LOG=rustc_codegen_ssa::back::link=info $(RUSTC) -Clink-self-contained=+linker -Zlinker-features=+lld -Zunstable-options -Clink-args=-Wl,-v main.rs 2> $(TMPDIR)/output.txt
 	$(CGREP) -e "^LLD [0-9]+\.[0-9]+\.[0-9]+" < $(TMPDIR)/output.txt
+
+	# while we're here, also check that the last linker feature flag "wins"
+	RUSTC_LOG=rustc_codegen_ssa::back::link=info $(RUSTC) -Clink-self-contained=+linker -Zlinker-features=-lld -Zlinker-features=+lld -Zunstable-options -Clink-args=-Wl,-v main.rs 2> $(TMPDIR)/output.txt
+	$(CGREP) -e "^LLD [0-9]+\.[0-9]+\.[0-9]+" < $(TMPDIR)/output.txt