Make debugging great again.

Regarding the OutStreamer->finish() removal:
This fixes the "error: symbol '.Lline_table_start0' is already defined"
error that we had for a while (probably a bad rebase).
OutStreamer->finish() emits the debug line table (and its
line_table_start0 label). The second finish runs again and tries to
define the same label, which triggers the “already defined” error.

Author: adriweb

llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp

@@ -2385,8 +2385,6 @@ bool AsmPrinter::doFinalization(Module &M) {
     }
   }
 
-  OutStreamer->finish();
-
   // Allow the target to emit any magic that it wants at the end of the file,
   // after everything else has gone out.
   emitEndOfAsmFile(M);

llvm/lib/Target/Z80/MCTargetDesc/Z80MCAsmInfo.cpp

@@ -43,6 +43,7 @@ Z80MCAsmInfoELF::Z80MCAsmInfoELF(const Triple &T) {
   AssemblerDialect = !Is16Bit;
   HasFunctionAlignment = false;
   ExceptionsType = ExceptionHandling::SjLj;
+  SupportsDebugInformation = SupportsCFI = true;
 
   if (Z80GasStyle) {
     Code16Directive = ".assume\tADL = 0";
@@ -88,7 +89,6 @@ Z80MCAsmInfoELF::Z80MCAsmInfoELF(const Triple &T) {
     WeakDirective = "\tweak\t";
     UseLogicalShr = false;
     HasSingleParameterDotFile = false;
-    SupportsDebugInformation = SupportsCFI = true;
     DwarfFileDirective = "\tfile\t";
     DwarfLocDirective = "\tloc\t";
     DwarfCFIDirectivePrefix = "\tcfi_";