[SystemZ] Add CodeGen test cases

This adds all CodeGen tests for the SystemZ target.

This version of the patch incorporates feedback from a review by
Sean Silva.  Thanks to all reviewers!

Patch by Richard Sandiford.

llvm-svn: 181204
diff --git a/llvm/test/CodeGen/SystemZ/branch-01.ll b/llvm/test/CodeGen/SystemZ/branch-01.ll
new file mode 100644
index 0000000..8ff91ac
--- /dev/null
+++ b/llvm/test/CodeGen/SystemZ/branch-01.ll
@@ -0,0 +1,14 @@
+; Test a simple unconditional jump.
+;
+; RUN: llc < %s -mtriple=s390x-linux-gnu | FileCheck %s
+
+define void @f1(i8 *%dest) {
+; CHECK: f1:
+; CHECK: .L[[LABEL:.*]]:
+; CHECK: mvi 0(%r2), 1
+; CHECK: j{{g?}} .L[[LABEL]]
+  br label %loop
+loop:
+  store volatile i8 1, i8 *%dest
+  br label %loop
+}