Fix a bug handling hex floats in c90 mode, pointed out by Neil.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@44120 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/test/Lexer/c90.c b/test/Lexer/c90.c
new file mode 100644
index 0000000..84d3046
--- /dev/null
+++ b/test/Lexer/c90.c
@@ -0,0 +1,5 @@
+// RUN: clang -std=c90 -fsyntax-only %s -verify
+
+enum { cast_hex = (long) (
+      0x0p-1   /* expected-error {{invalid suffix 'p' on integer constant}} */
+     ) };