Fix a weird inconsistency with hex floats.  Previously the lexer 
would not eat the "-1" in "0x0p-1", but LiteralSupport would accept
it when extensions are on.  This caused strangeness and failures 
when hexfloats were properly treated as an extension (not error)
in LiteralSupport.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@59865 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Lex/Lexer.cpp b/lib/Lex/Lexer.cpp
index b4d0717..1e9789b 100644
--- a/lib/Lex/Lexer.cpp
+++ b/lib/Lex/Lexer.cpp
@@ -574,8 +574,8 @@
     return LexNumericConstant(Result, ConsumeChar(CurPtr, Size, Result));
 
   // If we have a hex FP constant, continue.
-  if (Features.HexFloats &&
-      (C == '-' || C == '+') && (PrevCh == 'P' || PrevCh == 'p'))
+  if ((C == '-' || C == '+') && (PrevCh == 'P' || PrevCh == 'p') &&
+      (Features.HexFloats || !Features.NoExtensions))
     return LexNumericConstant(Result, ConsumeChar(CurPtr, Size, Result));
   
   // Update the location of token as well as BufferPtr.