Rollup merge of #140457 - fneddy:fix_s390x_codegen_const_vector, r=Mark-Simulacrum

Use target-cpu=z13 on s390x codegen const vector test

The default s390x cpu(z10) does not have vector support. Setting target-cpu at least to z13 enables vectorisation for s390x architecture and makes the test pass.

Author: tgross35