Remove unused pc descriptor types.

runtime/vm/intermediate_language_arm64.cc

Index: runtime/vm/intermediate_language_arm64.cc
diff --git a/runtime/vm/intermediate_language_arm64.cc b/runtime/vm/intermediate_language_arm64.cc
index d6b87182bb81156cf3b1faa4d740b4f5f5465ac3..a26030244a92bae2e97bd595740efed05ece7b92 100644
--- a/runtime/vm/intermediate_language_arm64.cc
+++ b/runtime/vm/intermediate_language_arm64.cc
@@ -222,22 +222,19 @@ void ClosureCallInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
   __ LoadImmediate(R5, 0, PP);
   __ AddImmediate(R2, R2, Instructions::HeaderSize() - kHeapObjectTag, PP);
   __ blr(R2);
-  compiler->AddCurrentDescriptor(RawPcDescriptors::kClosureCall,
-                                 deopt_id(),
-                                 token_pos());
   compiler->RecordSafepoint(locs());
   // Marks either the continuation point in unoptimized code or the
   // deoptimization point in optimized code, after call.
   const intptr_t deopt_id_after = Isolate::ToDeoptAfter(deopt_id());
   if (compiler->is_optimizing()) {
     compiler->AddDeoptIndexAtCall(deopt_id_after, token_pos());
-  } else {
-    // Add deoptimization continuation point after the call and before the
-    // arguments are removed.
-    compiler->AddCurrentDescriptor(RawPcDescriptors::kDeopt,
-                                   deopt_id_after,
-                                   token_pos());
   }
+  // Add deoptimization continuation point after the call and before the
+  // arguments are removed.
+  // In optimized code this descriptor is needed for exception handling.
+  compiler->AddCurrentDescriptor(RawPcDescriptors::kDeopt,
+                                 deopt_id_after,
+                                 token_pos());
   __ Drop(argument_count);
 }