* Correct main/self thread functions

packages/wasi/src/rtl.threadcontroller.pas

@@ -74,7 +74,6 @@ Type
     function thread_spawn(start_arg : longint) : longint; override;
     Function thread_detach(thread_id : longint) : Integer; override;
     Function thread_cancel(thread_id : longint) : Integer; override;
-    Function thread_self() : Integer; override;
   Protected
     FIdleWorkers : Array of TWasmThread;
     FBusyWorkers : Array of TWasmThread;
@@ -354,12 +353,6 @@ begin
   Result:=-1;
 end;
 
-function TThreadController.thread_self: Integer;
-begin
-  Result:=-1;
-end;
-
-
 procedure TThreadController.SendLoadCommands;
 
 Var

packages/wasi/src/rtl.webthreads.pas

@@ -292,9 +292,11 @@ Type
 
     // Proposed WASI standard, modeled after POSIX pthreads.
     function thread_spawn(start_arg : longint) : longint; virtual; abstract;
+    // These are extensions
     Function thread_detach(thread_id : longint) : Integer; virtual; abstract;
     Function thread_cancel(thread_id : longint) : Integer; virtual; abstract;
-    Function thread_self() : Integer; virtual; abstract;
+    Function thread_self() : Integer; virtual;
+    Function thread_main() : Integer; virtual;
   Public
     Function ImportName : String; override;
     procedure FillImportObject(aObject: TJSObject); override;
@@ -498,6 +500,34 @@ end;
 
 { TWasmThreadSupport }
 
+function TWasmThreadSupport.thread_self(): Integer;
+
+Type
+  TGetThreadIDFunction = Function : Longint;
+var
+  F : TGetThreadIDFunction;
+begin
+  F:=TGetThreadIDFunction(InstanceExports['GetSelfThread']);
+  if Assigned(F) then
+    Result:=F()
+  else
+    Result:=0;
+end;
+
+function TWasmThreadSupport.thread_main: Integer;
+
+Type
+  TGetThreadIDFunction = Function : Longint;
+var
+  F : TGetThreadIDFunction;
+begin
+  F:=TGetThreadIDFunction(InstanceExports['GetMainThread']);
+  if Assigned(F) then
+    Result:=F()
+  else
+    Result:=0;
+end;
+
 function TWasmThreadSupport.ImportName: String;
 begin
   Result:='wasi';

packages/wasi/src/wasiworkerthreadhost.pas

@@ -77,7 +77,6 @@ Type
     function thread_spawn(start_arg : longint) : longint; override;
     Function thread_detach(thread_id : Integer) : Integer; override;
     Function thread_cancel(thread_id : Integer) : Integer; override;
-    Function thread_self() : Integer; override;
   Public
     // Handle incoming command
     Procedure HandleCommand(aCommand : TWorkerCommand); override;
@@ -332,10 +331,6 @@ begin
   if thread_id=0 then ;
 end;
 
-function TWorkerThreadSupport.thread_self: Integer;
-begin
-  Result:=0;
-end;
 
 procedure TWorkerThreadSupport.SendLoaded;