[AVR] Don't adjust addresses by 2 for absolute values

Adjusting by 2 breaks DWARF output. With this fix, programs start to
compile and produce valid DWARF output.

Differential Revision: https://reviews.llvm.org/D74213

llvm/lib/Target/AVR/MCTargetDesc/AVRAsmBackend.cpp

@@ -244,8 +244,18 @@ void AVRAsmBackend::adjustFixupValue(const MCFixup &Fixup,
   // To handle both cases, we simply un-adjust the temporary label
   // case so it acts like all other labels.
   if (const MCSymbolRefExpr *A = Target.getSymA()) {
-    if (A->getSymbol().isTemporary())
-      Value += 2;
+    if (A->getSymbol().isTemporary()) {
+      switch (Kind) {
+      case FK_Data_1:
+      case FK_Data_2:
+      case FK_Data_4:
+      case FK_Data_8:
+        // Don't shift value for absolute addresses.
+        break;
+      default:
+        Value += 2;
+      }
+    }
   }
 
   switch (Kind) {

llvm/test/MC/AVR/relocations-abs.s

@@ -0,0 +1,8 @@
+; RUN: llvm-mc -filetype=obj -triple=avr %s | llvm-objdump -dr - | FileCheck %s
+
+; CHECK: bar:
+; CHECK-NEXT: 00 00 nop
+; CHECK-NEXT: R_AVR_16 .text+0x2
+bar:
+    .short 1f
+1: