[RISCV] Define PendingArgFlags function in CallingConvLower.h

[mgrang]

Summary

This fixes build error due to missing function definition.

[sabuasal]

@asb approved this here: https://reviews.llvm.org/D39898

[mgrang]

This is fixed in D39898. Abandoning this.

include/llvm/CodeGen/CallingConvLower.h

private:
   const TargetRegisterInfo &TRI;
   SmallVectorImpl<CCValAssign> &Locs;
   LLVMContext &Context;
 
   unsigned StackOffset;
   unsigned MaxStackArgAlign;
   SmallVector<uint32_t, 16> UsedRegs;
   SmallVector<CCValAssign, 4> PendingLocs;
+  SmallVector<ISD::ArgFlagsTy, 4> PendingArgFlags;
 
   // ByValInfo and SmallVector<ByValInfo, 4> ByValRegs:
   //
   // Vector of ByValInfo instances (ByValRegs) is introduced for byval registers
   // tracking.
   // Or, in another words it tracks byval parameters that are stored in
   // general purpose registers.
   //
void clearByValRegsInfo() {
     ByValRegs.clear();
   }
 
   // Rewind byval registers tracking info.
   void rewindByValRegsInfo() {
     InRegsParamsProcessed = 0;
   }
 
-  // Get list of pending assignments
+  // Get list of pending assignments.
   SmallVectorImpl<CCValAssign> &getPendingLocs() {
     return PendingLocs;
   }
 
+  // Get a list of argflags for pending assignments.
+  SmallVectorImpl<ISD::ArgFlagsTy> &getPendingArgFlags() {
+    return PendingArgFlags;
+  }
+
   /// Compute the remaining unused register parameters that would be used for
   /// the given value type. This is useful when varargs are passed in the
   /// registers that normal prototyped parameters would be passed in, or for
   /// implementing perfect forwarding.
   void getRemainingRegParmsForType(SmallVectorImpl<MCPhysReg> &Regs, MVT VT,
                                    CCAssignFn Fn);
 
   /// Compute the set of registers that need to be preserved and forwarded to