Applied in changeset trunk|r61659.

Speedup block.call [Feature ]

• insns.def (getblockparamproxy): introduce new instruction to return
  the rb_block_param_proxy object if possible. This object responds
  to call method and invoke given block (completely similar to yield).

• method.h (OPTIMIZED_METHOD_TYPE_BLOCK_CALL): add new optimized call type
  which is for rb_block_param_proxy.cal.

• vm_insnhelper.c (vm_call_method_each_type): ditto.

• vm_insnhelper.c (vm_call_opt_block_call): ditto.

• vm_core.h (BOP_CALL, PROC_REDEFINED_OP_FLAG): add check for Proc#call
  redefinition.

• compile.c (iseq_compile_each0): compile to use new insn
  getblockparamproxy for method call.