PR c++/69662 - -Wplacement-new on allocated one element array members

PR c++/69662 - -Wplacement-new on allocated one element array members

gcc/testsuite/ChangeLog:
	PR c++/69662
	* g++.dg/warn/Wplacement-new-size-1.C: New test.
	* g++.dg/warn/Wplacement-new-size-2.C: New test.

gcc/cp/ChangeLog:
	PR c++/69662
	* init.c (find_field_init): New function.
	(warn_placement_new_too_small): Call it.  Handle one-element arrays
        at ends of structures special.

gcc/c-family/ChangeLog:
	PR c++/69662
	* c.opt (Warning options): Update -Wplacement-new to take
        an optional argument.

gcc/ChangeLog:
	PR c++/69662
	* doc/invoke.texi: Update -Wplacement-new to take an optional
        argument.

From-SVN: r233190