[Arm64] Use REG_IP1 for genEpilogRestoreReg*

Avoid conflict with FASTTAILCALL_TARGET reg

Author: sdmaclea

src/jit/codegenarm64.cpp

@@ -653,11 +653,11 @@ void CodeGen::genRestoreCalleeSavedRegistersHelp(regMaskTP regsToRestoreMask, in
             maskRestoreRegsFloat &= ~reg1Mask;
             floatRegsToRestoreCount -= 1;
 
-            genEpilogRestoreRegPair(reg1, reg2, spOffset, stackDelta, REG_IP0, nullptr);
+            genEpilogRestoreRegPair(reg1, reg2, spOffset, stackDelta, REG_IP1, nullptr);
         }
         else
         {
-            genEpilogRestoreReg(reg2, spOffset, stackDelta, REG_IP0, nullptr);
+            genEpilogRestoreReg(reg2, spOffset, stackDelta, REG_IP1, nullptr);
         }
     }
 
@@ -702,11 +702,11 @@ void CodeGen::genRestoreCalleeSavedRegistersHelp(regMaskTP regsToRestoreMask, in
             maskRestoreRegsInt &= ~reg1Mask;
             intRegsToRestoreCount -= 1;
 
-            genEpilogRestoreRegPair(reg1, reg2, spOffset, stackDelta, REG_IP0, nullptr);
+            genEpilogRestoreRegPair(reg1, reg2, spOffset, stackDelta, REG_IP1, nullptr);
         }
         else
         {
-            genEpilogRestoreReg(reg2, spOffset, stackDelta, REG_IP0, nullptr);
+            genEpilogRestoreReg(reg2, spOffset, stackDelta, REG_IP1, nullptr);
         }
     }
 

src/jit/codegencommon.cpp

@@ -6824,7 +6824,7 @@ void CodeGen::genPopCalleeSavedRegistersAndFreeLclFrame(bool jmpEpilog)
                 // Generate:
                 //      ldp fp,lr,[sp]
                 //      add sp,sp,#remainingFrameSz
-                genEpilogRestoreRegPair(REG_FP, REG_LR, alignmentAdjustment2, spAdjustment2, REG_IP0, nullptr);
+                genEpilogRestoreRegPair(REG_FP, REG_LR, alignmentAdjustment2, spAdjustment2, REG_IP1, nullptr);
             }
             else
             {
@@ -6842,7 +6842,7 @@ void CodeGen::genPopCalleeSavedRegistersAndFreeLclFrame(bool jmpEpilog)
                 //      add sp,sp,#remainingFrameSz     ; might need to load this constant in a scratch register if
                 //                                      ; it's large
 
-                genEpilogRestoreRegPair(REG_FP, REG_LR, compiler->lvaOutgoingArgSpaceSize, remainingFrameSz, REG_IP0,
+                genEpilogRestoreRegPair(REG_FP, REG_LR, compiler->lvaOutgoingArgSpaceSize, remainingFrameSz, REG_IP1,
                                         nullptr);
             }