constexpr DynArray subscript gets evaluated at runtime

[cyberthirst]

Version Information

• vyper Version (output of vyper --version): 0.4.1b2+commit.f31ff46bd

• OS: osx/linux/win

• Python Version (output of python --version):

What's your issue about?

MAX: constant(DynArray[uint256, 10]) = [1, 2, 3]
a: constant(uint256) = MAX[3]

@external
def foo() -> uint256:
    return a

the subscript (including clamping) happens at runtime. we should promote the runtime error to a compile time error

How can it be fixed?

Fill this in if you know how to fix it.