[Darwin, PPC, testsuite] Fix pr80125 testcase for Darwin.

Darwin (unlike most of the members of the PowerPC port family)
defaults to signed chars, so the test was failing to compile with
a "mismatched parameters" error.

2019-06-23  Iain Sandoe  <iain@sandoe.co.uk>

	* gcc.target/powerpc/pr80125.c (foo): Use an unsigned char
	vector explicitly for the vec_perm.

From-SVN: r272605

gcc/testsuite/ChangeLog

 2019-06-23  Iain Sandoe  <iain@sandoe.co.uk>
 
+	* gcc.target/powerpc/pr80125.c (foo): Use an unsigned char
+	vector explicitly for the vec_perm.
+
+2019-06-23  Iain Sandoe  <iain@sandoe.co.uk>
+
 	* gcc.target/powerpc/builtins-1.c: Account for Darwin's use of
 	__USER_LABEL_PREFIX__.
 

gcc/testsuite/gcc.target/powerpc/pr80125.c

@@ -16,7 +16,7 @@ foo ()
   vector int k = vec_mergel (i, j);
   vector int l = vec_sl (k, c);
   vector int m = vec_sl (l, d);
-  vector char o;
+  vector unsigned char o;
   vector int p = vec_perm (m, n, o);
   e = vec_sra (p, c);
   vec_st (e, 0, a);