internal/ethapi/api: for simulated calls, set gaspool to max value if global gascap is 0 (ethereum#30474)

In ethereum#27720, we introduced RPC global gas cap. A value of `0` means an unlimited gas cap. However, this was not the case for simulated calls. This PR fixes the behaviour.

Author: jwasinger

internal/ethapi/api.go

@@ -1181,7 +1181,13 @@ func doCall(ctx context.Context, b Backend, args TransactionArgs, state *state.S
 	// Make sure the context is cancelled when the call has completed
 	// this makes sure resources are cleaned up.
 	defer cancel()
-	return applyMessage(ctx, b, args, state, header, timeout, new(core.GasPool).AddGas(globalGasCap), &blockCtx, &vm.Config{NoBaseFee: true}, precompiles, true)
+	gp := new(core.GasPool)
+	if globalGasCap == 0 {
+		gp.AddGas(math.MaxUint64)
+	} else {
+		gp.AddGas(globalGasCap)
+	}
+	return applyMessage(ctx, b, args, state, header, timeout, gp, &blockCtx, &vm.Config{NoBaseFee: true}, precompiles, true)
 }
 
 func applyMessage(ctx context.Context, b Backend, args TransactionArgs, state *state.StateDB, header *types.Header, timeout time.Duration, gp *core.GasPool, blockContext *vm.BlockContext, vmConfig *vm.Config, precompiles vm.PrecompiledContracts, skipChecks bool) (*core.ExecutionResult, error) {