As the testcase shows, some EXEC_OACC_* codes weren't handled in
oacc_code_to_statement.  Fixed thusly.

2020-01-29  Jakub Jelinek  <jakub@redhat.com>

	PR fortran/93463
	* openmp.c (oacc_code_to_statement): Handle
	EXEC_OACC_{ROUTINE,UPDATE,WAIT,CACHE,{ENTER,EXIT}_DATA,DECLARE}.

	* gfortran.dg/goacc/pr93463.f90: New test.