add test for #5425

testsuite/tests/parser/should_fail/T5425.hs

+
+-- load into ghci
+
+"λa: (Type[0] → (Type[0] → Type[0])).\
+ λb: (Type[0] → Type[0]). λc: Type[0].\
+   ((a c)(b c))"

testsuite/tests/parser/should_fail/T5425.stderr

+
+T5425.hs:5:2:
+    lexical error in string/character literal at character '\955'

testsuite/tests/parser/should_fail/all.T

@@ -73,3 +73,4 @@ test('readFailTraditionalRecords1', normal, compile_fail, [''])
 test('readFailTraditionalRecords2', normal, compile_fail, [''])
 test('readFailTraditionalRecords3', normal, compile_fail, [''])
 
+test('T5425', normal, compile_fail, [''])