Warning fixes:
* class.c (build_utf8_ref): Initialize variable `field'.
* decl.c (init_decl_processing): Initialize variable `field'.
* expr.c (build_known_method_ref): Mark parameters `method_type',
`method_signature' and `arg_list' with ATTRIBUTE_UNUSED.
(process_jvm_instruction): Likewise for parameter `length'.
* jvspec.c (lang_specific_driver): Mark variables `saw_math',
`saw_libc', `saw_gc', `saw_threadlib' and `saw_libgcj' with
ATTRIBUTE_UNUSED.
* parse.y (maybe_generate_clinit): Remove unused variable
`has_non_primitive_fields'.
(find_in_imports_on_demand): Initialize variables `node_to_use'
and `cl'.
(patch_binop): Likewise for variable `prom_type'.
(patch_unaryop): Likewise for variable `prom_type'.
* verify.c (verify_jvm_instructions): Likewise for variable `last'.
* xref.c (xref_table): Add missing initializer.
From-SVN: r27030