testsuite: Add -Wno-psabi option for ipa-sra-19.c on AIX.

ipa-sra-19.c uses a vector type that elicits a non-standard ABI warning
on AIX causing a spurious testsuite failure.

        * gcc.dg/ipa/ipa-sra-19.c: Add -Wno-psabi option on AIX.

gcc/testsuite/ChangeLog

 2020-04-25  David Edelsohn  <dje.gcc@gmail.com>
 
+	* gcc.dg/ipa/ipa-sra-19.c: Add -Wno-psabi option on AIX.
+
+2020-04-25  David Edelsohn  <dje.gcc@gmail.com>
+
 	* gcc.dg/spellcheck-options-21.c: Require LTO.
 
 2020-04-25  David Edelsohn  <dje.gcc@gmail.com>

gcc/testsuite/gcc.dg/ipa/ipa-sra-19.c

 /* { dg-do compile } */
 /* { dg-options "-O2"  } */
 /* { dg-additional-options "-msse2" { target ia32 } } */
+/* { dg-additional-options "-Wno-psabi" { target powerpc-ibm-aix* } } */
 
 typedef int __attribute__((__vector_size__(16))) vectype;