Fix g++ testsuite failure caused by std::is_pod deprecation

	PR testsuite/93227
	* g++.dg/cpp0x/std-layout1.C: Use -Wno-deprecated-declarations for
	C++20, due to std::is_pod being deprecated.

gcc/testsuite/ChangeLog

+2020-01-17  Jonathan Wakely  <jwakely@redhat.com>
+
+	PR testsuite/93227
+	* g++.dg/cpp0x/std-layout1.C: Use -Wno-deprecated-declarations for
+	C++20, due to std::is_pod being deprecated.
+
 2020-01-17  Matthew Malcomson  <matthew.malcomson@arm.com>
 
 	* gcc.target/aarch64/sve/acle/asm/ld1ro_f16.c: New test.

gcc/testsuite/g++.dg/cpp0x/std-layout1.C

 // { dg-do compile { target c++11 } }
+// { dg-additional-options "-Wno-deprecated-declarations" { target c++2a } }
 
 // [basic.types]/10:
 // Scalar types, standard-layout class types (Clause 9), arrays of such