MIPS64: Add support for architecture revision 6.

src/mips64/constants-mips64.cc

Index: src/mips64/constants-mips64.cc
diff --git a/src/mips64/constants-mips64.cc b/src/mips64/constants-mips64.cc
index 04f4bbc52f88960467c207917235b88463b1865a..dfd62430c29c355ea7a4254c46a66c42594ea185 100644
--- a/src/mips64/constants-mips64.cc
+++ b/src/mips64/constants-mips64.cc
@@ -295,6 +295,8 @@ Instruction::Type Instruction::InstructionType() const {
     case COP1:    // Coprocessor instructions.
       switch (RsFieldRawNoAssert()) {
         case BC1:   // Branch on coprocessor condition.
+        case BC1EQZ:
+        case BC1NEZ:
           return kImmediateType;
         default:
           return kRegisterType;
@@ -322,6 +324,8 @@ Instruction::Type Instruction::InstructionType() const {
     case BNEL:
     case BLEZL:
     case BGTZL:
+    case BEQZC:
+    case BNEZC:
     case LB:
     case LH:
     case LWL: