[turbofan] OSR loops assign all local variables.

R=mstarzinger@chromium.org
BUG=

Review URL: https://codereview.chromium.org/886733005

Cr-Commit-Position: refs/heads/master@{#26493}

src/bit-vector.h

@@ -103,6 +103,8 @@ class BitVector : public ZoneObject {
     data_[i / kDataBits] |= (kOne << (i % kDataBits));
   }
 
+  void AddAll() { memset(data_, -1, sizeof(uintptr_t) * data_length_); }
+
   void Remove(int i) {
     DCHECK(i >= 0 && i < length());
     data_[i / kDataBits] &= ~(kOne << (i % kDataBits));

src/compiler/ast-loop-assignment-analyzer.cc

@@ -30,6 +30,8 @@ void ALAA::Enter(IterationStatement* loop) {
   int num_variables = 1 + info()->scope()->num_parameters() +
                       info()->scope()->num_stack_slots();
   BitVector* bits = new (zone()) BitVector(num_variables, zone());
+  if (info()->is_osr() && info()->osr_ast_id() == loop->OsrEntryId())
+    bits->AddAll();
   loop_stack_.push_back(bits);
 }