Add new function attribute - noredzone.

Update code generator to use this attribute and remove DisableRedZone target option.
Update llc to set this attribute when -disable-red-zone command line option is used.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@72894 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/Attributes.h

@@ -54,13 +54,15 @@ const Attributes Alignment = 31<<16; ///< Alignment of parameter (5 bits)
                                      // stored as log2 of alignment with +1 bias
                                      // 0 means unaligned different from align 1
 const Attributes NoCapture = 1<<21; ///< Function creates no aliases of pointer
+const Attributes NoRedZone = 1<<22; /// disable redzone
 
 /// @brief Attributes that only apply to function parameters.
 const Attributes ParameterOnly = ByVal | Nest | StructRet | NoCapture;
 
 /// @brief Attributes that only apply to function.
 const Attributes FunctionOnly = NoReturn | NoUnwind | ReadNone | ReadOnly | 
-  NoInline | AlwaysInline | OptimizeForSize | StackProtect | StackProtectReq;
+  NoInline | AlwaysInline | OptimizeForSize | StackProtect | StackProtectReq |
+  NoRedZone;
 
 /// @brief Parameter attributes that do not apply to vararg call arguments.
 const Attributes VarArgsIncompatible = StructRet;

include/llvm/Target/TargetOptions.h

@@ -117,10 +117,6 @@ namespace llvm {
   /// wth earlier copy coalescing.
   extern bool StrongPHIElim;
 
-  /// DisableRedZone - This flag disables use of the "Red Zone" on
-  /// targets which would otherwise have one.
-  extern bool DisableRedZone;
-
 } // End llvm namespace
 
 #endif