[turbofan] Implement the correct semantics for integer division/modulus.

src/base/bits.cc

Index: src/base/bits.cc
diff --git a/src/base/bits.cc b/src/base/bits.cc
index 2818b939aa94bb1c43761ef7add1386b0050c214..74d747fc9059f135cc2986b9b73f6ce473391534 100644
--- a/src/base/bits.cc
+++ b/src/base/bits.cc
@@ -3,6 +3,9 @@
 // found in the LICENSE file.
 
 #include "src/base/bits.h"
+
+#include <limits>
+
 #include "src/base/logging.h"
 
 namespace v8 {
@@ -32,6 +35,19 @@ int32_t SignedMulHighAndAdd32(int32_t lhs, int32_t rhs, int32_t acc) {
                            bit_cast<uint32_t>(SignedMulHigh32(lhs, rhs)));
 }
 
+
+int32_t SignedDiv32(int32_t lhs, int32_t rhs) {
+  if (rhs == 0) return 0;
+  if (rhs == -1) return -lhs;
+  return lhs / rhs;
+}
+
+
+int32_t SignedMod32(int32_t lhs, int32_t rhs) {
+  if (rhs == 0 || rhs == -1) return 0;
+  return lhs % rhs;
+}
+
 }  // namespace bits
 }  // namespace base
 }  // namespace v8