Fix Checked/Release asm diffs (#79844)

Code inside a `#ifdef DEBUG` had a side-effect not visible to
Release builds. Pull that code out of the `#ifdef`.

Fixes #79560

src/coreclr/jit/codegenxarch.cpp

@@ -3808,11 +3808,9 @@ void CodeGen::genCodeForCpObj(GenTreeObj* cpObjNode)
     // Make sure we got the arguments of the cpobj operation in the right registers
     GenTree*  dstAddr     = cpObjNode->Addr();
     GenTree*  source      = cpObjNode->Data();
-    GenTree*  srcAddr     = nullptr;
     var_types srcAddrType = TYP_BYREF;
     bool      dstOnStack  = dstAddr->gtSkipReloadOrCopy()->OperIsLocalAddr();
 
-#ifdef DEBUG
     // If the GenTree node has data about GC pointers, this means we're dealing
     // with CpObj, so this requires special logic.
     assert(cpObjNode->GetLayout()->HasGCPtr());
@@ -3824,7 +3822,10 @@ void CodeGen::genCodeForCpObj(GenTreeObj* cpObjNode)
     if (!source->IsLocal())
     {
         assert(source->gtOper == GT_IND);
-        srcAddr                   = source->gtGetOp1();
+        GenTree* srcAddr = source->gtGetOp1();
+        srcAddrType      = srcAddr->TypeGet();
+
+#ifdef DEBUG
         GenTree* actualSrcAddr    = srcAddr->gtSkipReloadOrCopy();
         GenTree* actualDstAddr    = dstAddr->gtSkipReloadOrCopy();
         unsigned srcLclVarNum     = BAD_VAR_NUM;
@@ -3845,9 +3846,8 @@ void CodeGen::genCodeForCpObj(GenTreeObj* cpObjNode)
                ((srcLclVarNum == dstLclVarNum) && !isDstAddrLiveOut));
         assert((actualDstAddr->GetRegNum() != REG_RDI) || !isDstAddrLiveOut ||
                ((srcLclVarNum == dstLclVarNum) && !isSrcAddrLiveOut));
-        srcAddrType = srcAddr->TypeGet();
-    }
 #endif // DEBUG
+    }
 
     // Consume the operands and get them into the right registers.
     // They may now contain gc pointers (depending on their type; gcMarkRegPtrVal will "do the right thing").