Add test for bug report #38973 (already fixed in trunk/main)

Fixed by in fixes_3_2 branch by cherry-pick commit g4e5fb2c

(cherry picked from commit 0bc827e9e26e8dcd65d0adaa23ccf0ffe6bbe2a6)

tests/webtbs/tw38973.pp

@@ -0,0 +1,12 @@
+{%OPT=-O2}
+{$mode objfpc}
+var
+     b : LongBOOL;
+     pb : ^LongBOOL;
+begin
+    b:=true;
+    pb:=nil;
+   if Assigned(pb) and pb^ then
+     Exit;
+    b:=false;
+end.