Revert of Remove SIMD.js from V8.

src/crankshaft/ia32/lithium-codegen-ia32.cc

Index: src/crankshaft/ia32/lithium-codegen-ia32.cc
diff --git a/src/crankshaft/ia32/lithium-codegen-ia32.cc b/src/crankshaft/ia32/lithium-codegen-ia32.cc
index 55fde013282d2e0a7fd5ea27ca086a54113a7566..29baf25c87607242ecdaf712003bae62ab783ca9 100644
--- a/src/crankshaft/ia32/lithium-codegen-ia32.cc
+++ b/src/crankshaft/ia32/lithium-codegen-ia32.cc
@@ -1927,6 +1927,12 @@
         __ j(equal, instr->TrueLabel(chunk_));
       }
 
+      if (expected & ToBooleanHint::kSimdValue) {
+        // SIMD value -> true.
+        __ CmpInstanceType(map, SIMD128_VALUE_TYPE);
+        __ j(equal, instr->TrueLabel(chunk_));
+      }
+
       if (expected & ToBooleanHint::kHeapNumber) {
         // heap number -> false iff +0, -0, or NaN.
         Label not_heap_number;
@@ -4907,6 +4913,18 @@
     __ test_b(FieldOperand(input, Map::kBitFieldOffset),
               Immediate((1 << Map::kIsCallable) | (1 << Map::kIsUndetectable)));
     final_branch_condition = zero;
+
+// clang-format off
+#define SIMD128_TYPE(TYPE, Type, type, lane_count, lane_type)         \
+  } else if (String::Equals(type_name, factory()->type##_string())) { \
+    __ JumpIfSmi(input, false_label, false_distance);                 \
+    __ cmp(FieldOperand(input, HeapObject::kMapOffset),               \
+           factory()->type##_map());                                  \
+    final_branch_condition = equal;
+  SIMD128_TYPES(SIMD128_TYPE)
+#undef SIMD128_TYPE
+    // clang-format on
+
   } else {
     __ jmp(false_label, false_distance);
   }