gcc/jit/ChangeLog:
	* jit-recording.c (class gcc::jit::rvalue_usage_validator): New.
	(gcc::jit::rvalue_usage_validator::rvalue_usage_validator): New
	ctor.
	(gcc::jit::rvalue_usage_validator::visit): New function.
	(gcc::jit::recording::rvalue::verify_valid_within_stmt): New
	function.
	(gcc::jit::recording::rvalue::set_scope): New function.
	(gcc::jit::recording::function::function): Call set_scope on each
	param, issuing errors for any params that already have a function.
	(gcc::jit::recording::block::add_eval): Return the new statement;
	update the comment given that some error-checking now happens after
	this returns.
	(gcc::jit::recording::block::add_assignment): Likewise.
	(gcc::jit::recording::block::add_assignment_op): Likewise.
	(gcc::jit::recording::block::add_comment): Likewise.
	(gcc::jit::recording::block::end_with_conditional): Likewise.
	(gcc::jit::recording::block::end_with_jump): Likewise.
	(gcc::jit::recording::block::end_with_return): Likewise.
	(gcc::jit::recording::block::validate): Add a comment.
	(gcc::jit::recording::unary_op::visit_children): New function.
	(gcc::jit::recording::binary_op::visit_children): New function.
	(gcc::jit::recording::comparison::visit_children): New function.
	(gcc::jit::recording::cast::visit_children): New function.
	(gcc::jit::recording::call::visit_children): New function.
	(gcc::jit::recording::call_through_ptr::visit_children): New function.
	(gcc::jit::recording::array_access::visit_children): New function.
	(gcc::jit::recording::access_field_of_lvalue::visit_children): New
	function.
	(gcc::jit::recording::access_field_rvalue::visit_children): New
	function.
	(gcc::jit::recording::dereference_field_rvalue::visit_children):
	New function.
	(gcc::jit::recording::dereference_rvalue::visit_children): New
	function.
	(gcc::jit::recording::get_address_of_lvalue::visit_children): New
	function.
	* jit-recording.h: Within namespace gcc::jit::recording...
	(class rvalue_visitor): New.
	(rvalue::rvalue): Initialize m_scope.
	(rvalue::get_loc): New accessor.
	(rvalue::verify_valid_within_stmt): New function.
	(rvalue::visit_children): New pure virtual function.
	(rvalue::set_scope): New function.
	(rvalue::get_scope): New function.
	(rvalue::dyn_cast_param): New function.
	(rvalue::m_scope): New field.
	(param::visit_children): New empty function.
	(param::dyn_cast_param): New function.
	(function::get_loc): New function.
	(block::add_eval): Return the new statement.
	(block::add_assignment): Likewise.
	(block::add_assignment_op): Likewise.
	(block::add_comment): Likewise.
	(block::end_with_conditional): Likewise.
	(block::end_with_jump): Likewise.
	(block::end_with_return): Likewise.
	(global::visit_children): New function.
	(memento_of_new_rvalue_from_const<HOST_TYPE>::visit_children):
	New function.
	(memento_of_new_string_literal::visit_children): New function.
	(unary_op::visit_children): New function.
	(binary_op::visit_children): New function.
	(comparison::visit_children): New function.
	(cast::visit_children): New function.
	(call::visit_children): New function.
	(call_through_ptr::visit_children): New function.
	(array_access::visit_children): New function.
	(access_field_of_lvalue::visit_children): New function.
	(access_field_rvalue::visit_children): New function.
	(dereference_field_rvalue::visit_children): New function.
	(dereference_rvalue::visit_children): New function.
	(get_address_of_lvalue::visit_children): New function.
	(local::local): Call set_scope.
	(local::visit_children): New function.
	(statement::get_block): Make public.
	* libgccjit.c (RETURN_VAL_IF_FAIL_PRINTF5): New macro.
	(RETURN_NULL_IF_FAIL_PRINTF5): New macro.
	(gcc_jit_context_new_function): Verify that each param has
	not yet been used for creating another function.
	(gcc_jit_block_add_eval): After creating the stmt, verify
	that the rvalue expression tree is valid to use within it.
	(gcc_jit_block_add_assignment): Likewise for the lvalue and
	rvalue expression trees.
	(gcc_jit_block_add_assignment_op): Likewise.
	(gcc_jit_block_end_with_conditional): Likewise for the boolval
	expression tree.
	(gcc_jit_block_end_with_return): Likewise for the rvalue
	expression tree.
	(gcc_jit_block_end_with_void_return): Remove return of "void",
	now that block::end_with_return is now non-void.

gcc/testsuite/ChangeLog:
	* jit.dg/test-error-local-used-from-other-function.c: New test
	case.
	* jit.dg/test-error-param-reuse.c: New test case.
	* jit.dg/test-error-param-sharing.c: New test case.
	* jit.dg/test-error-param-used-from-other-function.c: New test
	case.
	* jit.dg/test-error-param-used-without-a-function.c: New test
	case.

From-SVN: r219498