analyzer: add __analyzer_dump_state

analyzer: add __analyzer_dump_state

gcc/analyzer/ChangeLog:
	* engine.cc (exploded_node::on_stmt_pre): Handle
	__analyzer_dump_state.
	* program-state.cc (extrinsic_state::get_sm_idx_by_name): New.
	(program_state::impl_call_analyzer_dump_state): New.
	* program-state.h (extrinsic_state::get_sm_idx_by_name): New decl.
	(program_state::impl_call_analyzer_dump_state): New decl.
	* region-model-impl-calls.cc
	(call_details::get_arg_string_literal): New.
	* region-model.h (call_details::get_arg_string_literal): New decl.

gcc/ChangeLog:
	* doc/analyzer.texi: Add __analyzer_dump_state.

gcc/testsuite/ChangeLog:
	* gcc.dg/analyzer/analyzer-decls.h (__analyzer_dump_state): New.
	* gcc.dg/analyzer/dump-state.c: New test.

Signed-off-by: David Malcolm <dmalcolm@redhat.com>