[MIPS] Use break instruction as NACL_HALT for MIPS.

src/trusted/validator_mips/inst_classes.h

Index: src/trusted/validator_mips/inst_classes.h
diff --git a/src/trusted/validator_mips/inst_classes.h b/src/trusted/validator_mips/inst_classes.h
index 84e22409358af5e3b6aae2e10fdc017ce9fda919..02617377c09742a2241df5c43e2d662b44851e72 100644
--- a/src/trusted/validator_mips/inst_classes.h
+++ b/src/trusted/validator_mips/inst_classes.h
@@ -59,7 +59,7 @@ class ClassDecoder {
  public:
   /*
    * Checks how safe this instruction is, in isolation.
-   * This will detect any violation in the Mips spec -- undefined encodings,
+   * This will detect any violation in the MIPS spec -- undefined encodings,
    * use of registers that are unpredictable -- and the most basic constraints
    * in our SFI model.  Because ClassDecoders are referentially-transparent and
    * cannot touch global state, this will not check things that may vary with
@@ -169,7 +169,7 @@ class ClassDecoder {
 };
 
 /*
- * Current Mips NaCl halt (jr $zero).
+ * Current MIPS NaCl halt (break).
  */
 class NaClHalt : public ClassDecoder {
   public: