[AVR] Add the assembly instruction printer

Summary:
This change adds the AVR assembly instruction printer.

No tests are included in this patch. I have left them downstream so we can
add them once `llc` successfully runs (there's very few components left
to upstream until this).

Reviewers: arsenm, kparzysz

Subscribers: wdng, beanz, mgorny

Differential Revision: https://reviews.llvm.org/D25028

llvm-svn: 282854
diff --git a/llvm/lib/Target/AVR/CMakeLists.txt b/llvm/lib/Target/AVR/CMakeLists.txt
index 5f74790..42626d5 100644
--- a/llvm/lib/Target/AVR/CMakeLists.txt
+++ b/llvm/lib/Target/AVR/CMakeLists.txt
@@ -17,7 +17,8 @@
 
 add_dependencies(LLVMAVRCodeGen intrinsics_gen)
 
+add_subdirectory(AsmParser)
+add_subdirectory(InstPrinter)
 add_subdirectory(MCTargetDesc)
 add_subdirectory(TargetInfo)
-add_subdirectory(AsmParser)