PR78353: Fix testcases

Skip the test if arm7a is not supported at link time. This is the case
if the toolchain targets an M-profile CPU by default and does not have
A-profile multilib: the link step fails because it tries to mix
M-profile startup files with A-profile testcase.

2020-02-24  Christophe Lyon  <christophe.lyon@linaro.org>

	PR lto/78353
	* gcc.target/arm/pr78353-1.c: Add arm_arch_v7a_multilib effective
	target.
	* gcc.target/arm/pr78353-2.c: Likewise.

gcc/testsuite/ChangeLog

+2020-02-24  Christophe Lyon  <christophe.lyon@linaro.org>
+
+	PR lto/78353
+	* gcc.target/arm/pr78353-1.c: Add arm_arch_v7a_multilib effective
+	target.
+	* gcc.target/arm/pr78353-2.c: Likewise.
+
 2020-02-24  Jakub Jelinek  <jakub@redhat.com>
 
 	PR tree-optimization/93582

gcc/testsuite/gcc.target/arm/pr78353-1.c

 /* { dg-do link }  */
+/* { dg-require-effective-target arm_arch_v7a_multilib } */
 /* { dg-options "-march=armv7-a -mthumb -O2 -flto -Wa,-mimplicit-it=always" }  */
 
 int main(int x)

gcc/testsuite/gcc.target/arm/pr78353-2.c

 /* { dg-do link }  */
+/* { dg-require-effective-target arm_arch_v7a_multilib } */
 /* { dg-options "-march=armv7-a -mthumb -O2 -flto -Wa,-mimplicit-it=always,-mthumb" }  */
 
 int main(int x)