[AVR] Add ELF constants to headers

Also adds a 'trivial' ELF file. This was generated by assembling
and linking a file with the symbol main which contains a single
return instruction.

llvm-svn: 251096
diff --git a/llvm/lib/Object/ELFYAML.cpp b/llvm/lib/Object/ELFYAML.cpp
index 7a9cf6f..6866b4d 100644
--- a/llvm/lib/Object/ELFYAML.cpp
+++ b/llvm/lib/Object/ELFYAML.cpp
@@ -317,6 +317,25 @@
     BCase(EF_HEXAGON_ISA_V4)
     BCase(EF_HEXAGON_ISA_V5)
     break;
+  case ELF::EM_AVR:
+    BCase(EF_AVR_ARCH_AVR1)
+    BCase(EF_AVR_ARCH_AVR2)
+    BCase(EF_AVR_ARCH_AVR25)
+    BCase(EF_AVR_ARCH_AVR3)
+    BCase(EF_AVR_ARCH_AVR31)
+    BCase(EF_AVR_ARCH_AVR35)
+    BCase(EF_AVR_ARCH_AVR4)
+    BCase(EF_AVR_ARCH_AVR51)
+    BCase(EF_AVR_ARCH_AVR6)
+    BCase(EF_AVR_ARCH_AVRTINY)
+    BCase(EF_AVR_ARCH_XMEGA1)
+    BCase(EF_AVR_ARCH_XMEGA2)
+    BCase(EF_AVR_ARCH_XMEGA3)
+    BCase(EF_AVR_ARCH_XMEGA4)
+    BCase(EF_AVR_ARCH_XMEGA5)
+    BCase(EF_AVR_ARCH_XMEGA6)
+    BCase(EF_AVR_ARCH_XMEGA7)
+    break;
   default:
     llvm_unreachable("Unsupported architecture");
   }