Use file containing non-UTF-8 character instead of echo -e

src/test/run-make/stdin-non-utf8/Makefile

@@ -1,5 +1,6 @@
 -include ../tools.mk
 
 all:
-	echo -e '\xD2' | $(RUSTC) - 2>&1 \
+	cp non-utf8 $(TMPDIR)/non-utf.rs
+	cat $(TMPDIR)/non-utf.rs | $(RUSTC) - 2>&1 \
 		| $(CGREP) "error: couldn't read from stdin, as it did not contain valid UTF-8"

src/test/run-make/stdin-non-utf8/non-utf8

@@ -0,0 +1 @@
+<EFBFBD>