opcodes: aarch64: enforce checks on subclass flags in aarch64-gen.c

Enforce some checks on the newly added subclass flags:
  - If a subclass is set of one insn of an iclass, every insn of that
    iclass must have non-zero subclass field.
  - For all other iclasses, the subclass bits are zero for all insns.

include/
        * opcode/aarch64.h (enum aarch64_insn_class): Identify the
	maximum iclass enum value.

opcodes/
        * aarch64-gen.c (iclass_has_subclasses_p): New array of bool.
        (read_table): Enforce checks on subclass flags.

1 files changed, 2 insertions, 1 deletions

diff --git a/include/opcode/aarch64.h b/include/opcode/aarch64.h
index df07d3b..bc779c9 100644
--- a/include/opcode/aarch64.h
+++ b/include/opcode/aarch64.h
@@ -1110,7 +1110,8 @@ enum aarch64_insn_class
   sve2_urqvs,
   sve_index1,
   rcpc3,
-  lut
+  lut,
+  last_iclass = lut
 };
 
 /* Opcode enumerators.  */