c++: non-static memfn call dependence cleanup [PR106086]

In cp_parser_postfix_expression, and in the CALL_EXPR case of
tsubst_copy_and_build, we essentially repeat the type-dependent and
COMPONENT_REF callee cases of finish_call_expr.  This patch deduplicates
this logic by making both spots consistently go through finish_call_expr.

This allows us to easily fix PR106086 -- which is about us neglecting to
capture 'this' when we resolve a use of a non-static member function of
the current instantiation only at lambda regeneration time -- by moving
the call to maybe_generic_this_capture from the parser to finish_call_expr
so that we consider capturing 'this' at regeneration time as well.

	PR c++/106086

gcc/cp/ChangeLog:

	* parser.cc (cp_parser_postfix_expression): Consolidate three
	calls to finish_call_expr, one to build_new_method_call and
	one to build_min_nt_call_vec into one call to finish_call_expr.
	Don't call maybe_generic_this_capture here.
	* pt.cc (tsubst_copy_and_build) <case CALL_EXPR>: Remove
	COMPONENT_REF callee handling.
	(type_dependent_expression_p): Use t_d_object_e_p instead of
	t_d_e_p for COMPONENT_REF and OFFSET_REF.
	* semantics.cc (finish_call_expr): In the type-dependent case,
	call maybe_generic_this_capture here instead.

gcc/testsuite/ChangeLog:

	* g++.dg/template/crash127.C: Expect additional error due to
	being able to check the member access expression ahead of time.
	Strengthen the test by not instantiating the class template.
	* g++.dg/cpp1y/lambda-generic-this5.C: New test.