Fix some typos in art/compiler/optimizing/nodes.cc.

Change-Id: I11be5a9b73da207c9eb497bcaffc49d614c1ca89
diff --git a/compiler/optimizing/nodes.cc b/compiler/optimizing/nodes.cc
index c83340b..e08e8fb 100644
--- a/compiler/optimizing/nodes.cc
+++ b/compiler/optimizing/nodes.cc
@@ -162,7 +162,7 @@
   // (6) Compute the dominance information and the reverse post order.
   ComputeDominanceInformation();
 
-  // (7) Analyze loops discover through back edge analysis, and
+  // (7) Analyze loops discovered through back edge analysis, and
   //     set the loop information on each block.
   GraphAnalysisResult result = AnalyzeLoops();
   if (result != kAnalysisSuccess) {
@@ -247,7 +247,7 @@
   }
 
   // Populate `dominated_blocks_` information after computing all dominators.
-  // The potential presence of irreducible loops require to do it after.
+  // The potential presence of irreducible loops requires to do it after.
   for (HReversePostOrderIterator it(*this); !it.Done(); it.Advance()) {
     HBasicBlock* block = it.Current();
     if (!block->IsEntryBlock()) {
@@ -460,7 +460,7 @@
     if (block->IsLoopHeader()) {
       SimplifyLoop(block);
     } else if (!block->IsEntryBlock() && block->GetFirstInstruction()->IsSuspendCheck()) {
-      // We are being called by the dead code elimiation pass, and what used to be
+      // We are being called by the dead code elimination pass, and what used to be
       // a loop got dismantled. Just remove the suspend check.
       block->RemoveInstruction(block->GetFirstInstruction());
     }
@@ -2373,7 +2373,7 @@
   env_uses_.Clear();
 }
 
-// Returns an instruction with the opposite boolean value from 'cond'.
+// Returns an instruction with the opposite Boolean value from 'cond'.
 HInstruction* HGraph::InsertOppositeCondition(HInstruction* cond, HInstruction* cursor) {
   ArenaAllocator* allocator = GetArena();