Restructure inlining of Bigint accessors, use consistent approach, fixes a potential crash.

runtime/vm/flow_graph_optimizer.cc

Index: runtime/vm/flow_graph_optimizer.cc
===================================================================
--- runtime/vm/flow_graph_optimizer.cc	(revision 41839)
+++ runtime/vm/flow_graph_optimizer.cc	(working copy)
@@ -2970,57 +2970,6 @@
     return true;
   }
 
-  if ((recognized_kind == MethodRecognizer::kBigint_setUsed) &&
-      (ic_data.NumberOfChecks() == 1) &&
-      (class_ids[0] == kBigintCid)) {
-    // This is an internal method, no need to check argument types nor
-    // range.
-    Definition* bigint = call->ArgumentAt(0);
-    Definition* value = call->ArgumentAt(1);
-    StoreInstanceFieldInstr* store = new(I) StoreInstanceFieldInstr(
-        Bigint::used_offset(),
-        new(I) Value(bigint),
-        new(I) Value(value),
-        kNoStoreBarrier,
-        call->token_pos());
-    ReplaceCall(call, store);
-    return true;
-  }
-
-  if ((recognized_kind == MethodRecognizer::kBigint_setDigits) &&
-      (ic_data.NumberOfChecks() == 1) &&
-      (class_ids[0] == kBigintCid)) {
-    // This is an internal method, no need to check argument types nor
-    // range.
-    Definition* bigint = call->ArgumentAt(0);
-    Definition* value = call->ArgumentAt(1);
-    StoreInstanceFieldInstr* store = new(I) StoreInstanceFieldInstr(
-        Bigint::digits_offset(),
-        new(I) Value(bigint),
-        new(I) Value(value),
-        kEmitStoreBarrier,
-        call->token_pos());
-    ReplaceCall(call, store);
-    return true;
-  }
-
-  if ((recognized_kind == MethodRecognizer::kBigint_setNeg) &&
-      (ic_data.NumberOfChecks() == 1) &&
-      (class_ids[0] == kBigintCid)) {
-    // This is an internal method, no need to check argument types nor
-    // range.
-    Definition* bigint = call->ArgumentAt(0);
-    Definition* value = call->ArgumentAt(1);
-    StoreInstanceFieldInstr* store = new(I) StoreInstanceFieldInstr(
-        Bigint::neg_offset(),
-        new(I) Value(bigint),
-        new(I) Value(value),
-        kEmitStoreBarrier,
-        call->token_pos());
-    ReplaceCall(call, store);
-    return true;
-  }
-
   if (((recognized_kind == MethodRecognizer::kStringBaseCodeUnitAt) ||
        (recognized_kind == MethodRecognizer::kStringBaseCharAt)) &&
       (ic_data.NumberOfChecks() == 1) &&