ubsan: wasm32: signed integer overflow

ubsan: wasm32: signed integer overflow

The signed integer overflow occurred when adding one to target_count
  for (i = 0; i < target_count + 1; i++)
but that's the least of the worries here.  target_count was long and i
int, leading to the possibility of a loop that never ended.

So to avoid this type of vulnerability, this patch uses what I believe
to be the proper types for arguments of various wasm32 opcodes, rather
than using "long" which may change in size.

gas/
	* testsuite/gas/wasm32/allinsn.d: Update expected output.
opcodes/
	* wasm32-dis.c (print_insn_wasm32): Localise variables.  Store
	result of wasm_read_leb128 in a uint64_t and check that bits
	are not lost when copying to other locals.  Use uint32_t for
	most locals.  Use PRId64 when printing int64_t.