Revert of MIPS: [turbofan] Fix addition for deoptimization.

src/mips/macro-assembler-mips.cc

Index: src/mips/macro-assembler-mips.cc
diff --git a/src/mips/macro-assembler-mips.cc b/src/mips/macro-assembler-mips.cc
index 83436ee4aa14ac81868accab9d78e1175fe79bc8..3b8d8b1772a2eb40a3807549c01e371cd6542ee9 100644
--- a/src/mips/macro-assembler-mips.cc
+++ b/src/mips/macro-assembler-mips.cc
@@ -5493,14 +5493,11 @@
     DCHECK(!right.is(scratch));
 
     if (left.is(right) && dst.is(left)) {
-      mov(scratch, left);                // Preserve left and right.
-      addu(dst, left, right);            // Both are overwritten.
-      xor_(overflow_dst, dst, scratch);  // Left and right are equal.
-      Label done;                        // Restore inputs if overflow.
-      Branch(&done, ge, overflow_dst, Operand(zero_reg));
-      mov(left, scratch);  // Original left and right.
-      bind(&done);
-    } else if (dst.is(left)) {
+      mov(overflow_dst, right);
+      right = overflow_dst;
+    }
+
+    if (dst.is(left)) {
       mov(scratch, left);           // Preserve left.
       addu(dst, left, right);       // Left is overwritten.
       xor_(scratch, dst, scratch);  // Original left.