implement PR3940: #line numbers not fully checked


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@69403 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/test/Preprocessor/line-directive.c b/test/Preprocessor/line-directive.c
index 1dd8b29..8877406 100644
--- a/test/Preprocessor/line-directive.c
+++ b/test/Preprocessor/line-directive.c
@@ -68,3 +68,5 @@
 #line 2 "foo.c" EMPTY( )
 #line 2 "foo.c" NONEMPTY( )  // expected-warning{{extra tokens at end of #line directive}}
 
+// PR3940
+#line 0xf  // expected-warning {{#line directive requires decimal line number}}