[AVR] Document some public functions

llvm-svn: 337122
diff --git a/llvm/lib/Target/AVR/AVR.h b/llvm/lib/Target/AVR/AVR.h
index 2535b63..48327fd 100644
--- a/llvm/lib/Target/AVR/AVR.h
+++ b/llvm/lib/Target/AVR/AVR.h
@@ -37,8 +37,10 @@
 /// Contains the AVR backend.
 namespace AVR {
 
+/// An integer that identifies all of the supported AVR address spaces.
 enum AddressSpace { DataMemory, ProgramMemory };
 
+/// Checks if a given type is a pointer to program memory.
 template <typename T> bool isProgramMemoryAddress(T *V) {
   return cast<PointerType>(V->getType())->getAddressSpace() == ProgramMemory;
 }