dbgllvm: add scopeLine attribute for function debug info

Ensures that breaking on the function correctly sets the breakpoint on the
first source line of the function (rather than potentially in the prologue
without line information)

compiler/llvm/dbgllvm.pas

@@ -1214,7 +1214,6 @@ implementation
         fileref        : tai_simpletypedconst;
         procdeftai     : tai;
         st             : tsymtable;
-        prologfileinfo : pfileposinfo;
         vmtoffset      : pint;
         dispflags      : TSymStr;
         in_currentunit : boolean;
@@ -1259,7 +1258,6 @@ implementation
 
         { we have to attach the debug info to the definition instruction of the
           proc }
-        prologfileinfo:=nil;
         procdeftai:=nil;
         if in_currentunit then
           begin
@@ -2445,8 +2443,9 @@ implementation
         hp: tai;
         functionscope,
         positionmeta: tai_llvmspecialisedmetadatanode;
-        procdeffileindex: tfileposfileindex;
+        procdeffileinfo: tfileposinfo;
         nolineinfolevel : longint;
+        firstline: boolean;
       begin
         ensuremetainit;
         hp:=tai(list.first);
@@ -2458,15 +2457,16 @@ implementation
            end;
         if not assigned(hp) then
           exit;
-        procdeffileindex:=tprocdef(taillvmdecl(hp).def).fileinfo.fileindex;
+        procdeffileinfo:=tprocdef(taillvmdecl(hp).def).fileinfo;
         { might trigger for certain kinds of internally generated code }
-        if procdeffileindex=0 then
+        if procdeffileinfo.fileindex=0 then
           exit;
 
         functionscope:=def_meta_node(taillvmdecl(hp).def);
 
         nolineinfolevel:=0;
         hp:=tai(hp.next);
+        firstline:=true;
         while assigned(hp) do
           begin
             case hp.typ of
@@ -2493,8 +2493,16 @@ implementation
                 { valid file -> add info }
                 if (tailineinfo(hp).fileinfo.fileindex<>0) then
                   begin
+                    if firstline and
+                       (nolineinfolevel=0) then
+                      begin
+                        functionscope.addint64('scopeLine',tailineinfo(hp).fileinfo.line);
+                        firstline:=false;
+                      end;
                     positionmeta:=filepos_getmetanode(tailineinfo(hp).fileinfo,procdeffileinfo,functionscope,nolineinfolevel<>0);
                   end
+                { LLVM requires line info for call instructions that may
+                  potentially be inlined }
                 else if taillvm(hp).llvmopcode=la_call then
                   begin
                     positionmeta:=filepos_getmetanode(tailineinfo(hp).fileinfo,procdeffileinfo,functionscope,true);