Remove unsupported --profile-dir flag and related code

runtime/vm/isolate.cc

Index: runtime/vm/isolate.cc
diff --git a/runtime/vm/isolate.cc b/runtime/vm/isolate.cc
index a7e46617fd74b5ca6ad6b1573c7f1eba25af71e7..583bdec5aa14a29a3d85de954f8570f2f712f71b 100644
--- a/runtime/vm/isolate.cc
+++ b/runtime/vm/isolate.cc
@@ -1102,9 +1102,6 @@ void Isolate::Shutdown() {
     // Dump all accumulated timer data for the isolate.
     timer_list_.ReportTimers();
 
-    // Write out profiler data if requested.
-    Profiler::WriteProfile(this);
-
     // Write out the coverage data if collection has been enabled.
     CodeCoverage::Write(this);