[turbofan] Fix OSR into functions where the expression stack is not empty.

src/compiler.h

Index: src/compiler.h
diff --git a/src/compiler.h b/src/compiler.h
index 11cec55dc58ccec0b997fe41d970c35420a0e853..611a41ba80bd47c639a5cc921075a5c0e0b3bd47 100644
--- a/src/compiler.h
+++ b/src/compiler.h
@@ -405,6 +405,12 @@ class CompilationInfo {
     ast_value_factory_owned_ = owned;
   }
 
+  int osr_expr_stack_height() { return osr_expr_stack_height_; }
+  void set_osr_expr_stack_height(int height) {
+    DCHECK(height >= 0);
+    osr_expr_stack_height_ = height;
+  }
+
 #if DEBUG
   void PrintAstForTesting();
 #endif
@@ -531,6 +537,8 @@ class CompilationInfo {
   // should be abandoned due to dependency change.
   bool aborted_due_to_dependency_change_;
 
+  int osr_expr_stack_height_;
+
   DISALLOW_COPY_AND_ASSIGN(CompilationInfo);
 };