iseq.c: prefix rb_ to non-static iseq functions

	I assume we always prefix rb_ to non-static functions to avoid conflict.
	These functions are not exported and safe to be renamed.

	iseq.h: ditto
	compile.c: ditto

	Fix TracePoint for nested iseq loaded from binary [Bug#14702]

	When loading iseq from binary while a TracePoint is on, we need to
	recompile instructions to their "trace_" variant. Before this commit
	we only recompiled instructions in the top level iseq, which meant
	that TracePoint was malfunctioning for code inside module/class/method
	definitions.

	* compile.c: Move rb_iseq_init_trace to rb_ibf_load_iseq_complete.
	  It is called on all iseqs during loading.

	* test_iseq.rb: Test that tracepoints fire within children iseq when
	  using load_from_binary.

	This patch is from: Alan Wu <XrXr@users.noreply.github.com>


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_5@66225 b2dd03c8-39d4-4d8f-98ff-823fe69b080e