Revert of Internalize strings in-place

src/x87/macro-assembler-x87.cc

Index: src/x87/macro-assembler-x87.cc
diff --git a/src/x87/macro-assembler-x87.cc b/src/x87/macro-assembler-x87.cc
index 3b3dcaf53f043b0ee1dc6a79f8aa4f004b71e3e2..005fa053ac0456b10b6309596f980ed7cb43535c 100644
--- a/src/x87/macro-assembler-x87.cc
+++ b/src/x87/macro-assembler-x87.cc
@@ -2415,13 +2415,11 @@
   const int kFlatOneByteStringTag =
       kStringTag | kOneByteStringTag | kSeqStringTag;
   // Interleave bits from both instance types and compare them in one check.
-  const int kShift = 8;
-  DCHECK_EQ(0, kFlatOneByteStringMask & (kFlatOneByteStringMask << kShift));
+  DCHECK_EQ(0, kFlatOneByteStringMask & (kFlatOneByteStringMask << 3));
   and_(scratch1, kFlatOneByteStringMask);
   and_(scratch2, kFlatOneByteStringMask);
-  shl(scratch2, kShift);
-  or_(scratch1, scratch2);
-  cmp(scratch1, kFlatOneByteStringTag | (kFlatOneByteStringTag << kShift));
+  lea(scratch1, Operand(scratch1, scratch2, times_8, 0));
+  cmp(scratch1, kFlatOneByteStringTag | (kFlatOneByteStringTag << 3));
   j(not_equal, failure);
 }