Remove unused pc descriptor types.

runtime/vm/intermediate_language_x64.cc

Index: runtime/vm/intermediate_language_x64.cc
diff --git a/runtime/vm/intermediate_language_x64.cc b/runtime/vm/intermediate_language_x64.cc
index a7bad0ae93136a7c569365d3d94ff6d3a4c3ca1d..830df847bc4a9f25b94238128a8c2bcbe8c5f3dd 100644
--- a/runtime/vm/intermediate_language_x64.cc
+++ b/runtime/vm/intermediate_language_x64.cc
@@ -6364,22 +6364,19 @@ void ClosureCallInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
   __ xorq(RBX, RBX);
   __ addq(RCX, Immediate(Instructions::HeaderSize() - kHeapObjectTag));
   __ call(RCX);
-  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);
 }