[AVR] Add a selection of CodeGen tests

Summary: This adds all of the CodeGen tests which currently pass.

Reviewers: arsenm, kparzysz

Subscribers: japaric, wdng

Differential Revision: https://reviews.llvm.org/D26388

llvm-svn: 286418
diff --git a/llvm/test/CodeGen/AVR/features/avr-tiny.ll b/llvm/test/CodeGen/AVR/features/avr-tiny.ll
new file mode 100644
index 0000000..726196b
--- /dev/null
+++ b/llvm/test/CodeGen/AVR/features/avr-tiny.ll
@@ -0,0 +1,9 @@
+; RUN: llc -mattr=avrtiny -O0 < %s -march=avr | FileCheck %s
+
+define i16 @reg_copy16(i16 %a) {
+; CHECK-LABEL: reg_copy16
+; CHECK: mov r18, r24
+; CHECK: mov r19, r25
+
+  ret i16 %a
+}