There is one jump to continuation (method prologue) in C2EntryBarrierStub [1].
The current max_size setting assumes the stub is within 1MB, which means a simple `jal` instruction [2].
So I just count one for this jump in JDK-8343121. This doesn't seem to break for various tests.
But I think we should remove this constraint assuming a `auipc+jalr` pair for this jump.

[1] https://github.com/openjdk/jdk/blob/master/src/hotspot/cpu/riscv/c2_CodeStubs_riscv.cpp#L66
[2] https://github.com/openjdk/jdk/blob/master/src/hotspot/cpu/riscv/macroAssembler_riscv.cpp#L965