[AVR] Add a function instrumentation pass

This will be used for an on-chip test suite.

llvm-svn: 289641
diff --git a/llvm/lib/Target/AVR/AVRTargetMachine.cpp b/llvm/lib/Target/AVR/AVRTargetMachine.cpp
index 9d10ef9..fb32629 100644
--- a/llvm/lib/Target/AVR/AVRTargetMachine.cpp
+++ b/llvm/lib/Target/AVR/AVRTargetMachine.cpp
@@ -80,6 +80,7 @@
 
   auto &PR = *PassRegistry::getPassRegistry();
   initializeAVRExpandPseudoPass(PR);
+  initializeAVRInstrumentFunctionsPass(PR);
   initializeAVRRelaxMemPass(PR);
 }