[ARC] [COMMITTED] Fix FASTMATH field.

Move FASTMATH to the right enum.

2019-08-30  Claudiu Zissulescu <claziss@gmail.com>

        * opcode/arc.h (FASTMATH): Move it from insn_class_t to
        insn_subclass_t enum.

include/opcode/arc.h

@@ -59,7 +59,6 @@ typedef enum
   EI,
   ENTER,
   FLOAT,
-  FASTMATH,
   INVALID,
   JLI,
   JUMP,
@@ -99,6 +98,7 @@ typedef enum
   DP       = (1U << 6),
   DPA      = (1U << 7),
   DPX      = (1U << 8),
+  FASTMATH = (1U << 23),
   LL64     = (1U << 9),
   MPY1E    = (1U << 10),
   MPY6E    = (1U << 11),