RelocInfo: fix source position decoding.

src/assembler.h

Index: src/assembler.h
diff --git a/src/assembler.h b/src/assembler.h
index 09159fed08ee7babde1bfd27d51af5ee117209c5..4cf843a2a0ebddb29e558edc4b568dffe34034fe 100644
--- a/src/assembler.h
+++ b/src/assembler.h
@@ -419,7 +419,7 @@ class RelocIterator: public Malloced {
   // If the given mode is wanted, set it in rinfo_ and return true.
   // Else return false. Used for efficiently skipping unwanted modes.
   bool SetMode(RelocInfo::Mode mode) {
-    return (mode_mask_ & 1 << mode) ? (rinfo_.rmode_ = mode, true) : false;
+    return (mode_mask_ & (1 << mode)) ? (rinfo_.rmode_ = mode, true) : false;
   }
 
   byte* pos_;