save-analysis: Test that we don't panic with malformed config

Author: Xanewok

src/test/run-make-fulldeps/save-analysis/Makefile

@@ -4,3 +4,5 @@ krate2: krate2.rs
 	$(RUSTC) $<
 code: foo.rs krate2
 	$(RUSTC) foo.rs -Zsave-analysis
+	# Don't panic on malformed config (uses default instead)
+	RUST_SAVE_ANALYSIS_CONFIG="{" $(RUSTC) foo.rs -Zsave-analysis