Const vs static

A proposal to extend statics/constants so that `static` always declares a global variable (memory location) with an address and `const` declares global *values*. `const` is what we expect users to use most of the time, `static` is only intended to be used in narrow circumstances.
@thestinger You seem to be responding to some text other than the one the comment is attached to, since that text doesn't mention mutability. Can you clarify what you mean? (That is, what concrete change does that imply for the proposal? Is there a restriction you think we ought to lift?)

However, I also want to point out that the semantics we choose here are not governed by what LLVM does -- that is, we could decide to inline or duplicate constants more aggressively (or less aggressively) than LLVM permits itself to do.