[committed] Fix mips testsuite fallout from vectorizer changes

[Jeff Law via Gcc-patches]

The mips ports have been failing msa-insert-split.c since the change to 
enabled the vectorizer at -O2.

This test expects to see insve, instructions to move data around. Those 
come as a result of the gimple optimizers using BIT_FIELD_REF expressions.

With vectorization we just emit a vector load and a vector store without 
any BIT_FIELD_REFs in gimple.  This translates into simple loads/stores 
and naturally the test fails.

Turning off the vectorizer seems like the right thing to do here.

Committed to the trunk,
Jeff
commit 8ececf9b8c5a2bf2f231db0c3bcf2be927990e7c
Author: Jeff Law <jeffreya...@gmail.com>
Date:   Thu Oct 14 10:49:05 2021 -0400

    Fix mips testsuite fallout from vectorizer changes
    
    gcc/testsuite
            * gcc.target/mips/msa-insert-split.c: Turn off vectorizer.

diff --git a/gcc/testsuite/gcc.target/mips/msa-insert-split.c 
b/gcc/testsuite/gcc.target/mips/msa-insert-split.c
index 50f3b8a61a1..9ad5987ac03 100644
--- a/gcc/testsuite/gcc.target/mips/msa-insert-split.c
+++ b/gcc/testsuite/gcc.target/mips/msa-insert-split.c
@@ -1,5 +1,5 @@
 /* { dg-do compile } */
-/* { dg-options "-mfp64 -mhard-float -mmsa" } */
+/* { dg-options "-fno-tree-vectorize -mfp64 -mhard-float -mmsa" } */
 /* { dg-skip-if "code quality test" { *-*-* } { "-O0" } { "" } } */
 
 typedef double v2f64 __attribute__ ((vector_size (16)));