Add Multidef Data Structures

Add a set of data structures and members analogous to those used for
multiclass defs.  These will represent a new kind of multiclass def: a
multidef.  The idea behind the multidef is to process a list of items
and create a def record for each one inside the enclosing multiclass.
This allows the user to dynamically create a set of defs based on the
contents of a list.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@141230 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/TableGen/Record.h

@@ -1568,6 +1568,23 @@ struct MultiClass {
   typedef std::vector<Record*> RecordVector;
   RecordVector DefPrototypes;
 
+  struct MultiDef {
+    Record *Rec;          // The base record for all defs generated.
+                          // This serves as the multiclass def prototype.
+    TypedInit *List;      // A list of values to process.
+                          // Each one generates a new def.
+    IntInit *Start;       // This specified the list index from which to start
+                          // processing.
+    std::string ItemName; // The name of a temporary iterator value to
+                          // track the current list item being processed.
+
+    MultiDef(Record *R, TypedInit *L, IntInit *S, const std::string &I) 
+        : Rec(R), List(L), Start(S), ItemName(I) {};
+  };
+
+  typedef std::vector<MultiDef> MultiDefVector;
+  MultiDefVector MultiDefPrototypes;
+
   void dump() const;
 
   MultiClass(const std::string &Name, SMLoc Loc, RecordKeeper &Records) :