Fix comment typos noticed by Bernhard

gcc/
	* tree-ssa-dom.cc (record_edge_info): Fix comment typos.
diff --git a/gcc/tree-ssa-dom.cc b/gcc/tree-ssa-dom.cc
index c7f095d..e82f4f7 100644
--- a/gcc/tree-ssa-dom.cc
+++ b/gcc/tree-ssa-dom.cc
@@ -673,10 +673,10 @@
 		{
 		  /* At this point we know the exit condition is loop
 		     invariant.  The only way to get out of the loop is
-		     if never traverses the backedge to begin with.  This
-		     implies that any PHI nodes create equivalances we can
-		     attach to the loop exit edge.  */
-		  int alternative
+		     if it never traverses the backedge to begin with.  This
+		     implies that any PHI nodes create equivalances that we
+		     can attach to the loop exit edge.  */
+		  int bool
 		    = (EDGE_PRED (bb, 0)->flags & EDGE_DFS_BACK) ? 1 : 0;
 
 		  gphi_iterator gsi;