analyze: rewriting sometimes produces non-Sync, non-mut statics

[spernsteiner]

Input:

static mut FOO: *mut u8 = std::ptr::null_mut();

We currently remove the mut, producing the following output:

static FOO: *mut u8 = std::ptr::null_mut();

However, this results in a compile error: *mut u8 is not Sync, so it can't be used as the type of a non-mut static. Note that mutable statics are exempt from this check, so the input code does not trigger a compile error.

[fw-immunant]

We do this if we see no writes to the static in the program. Types that don't admit writes are Sync, so it would be preferable (and sufficient to enable compilation) to change the type and rewrite use sites to match:

static FOO: Option<&mut u8> = None;

But we don't at present rewrite pointer types for statics, which seems like the right way to fix this.

[aneksteind]

@spernsteiner would one temporary solution be to mark these FIXED to address other more fundamental forms of rewritten-code compilation errors, and then come back to this?

[aneksteind]

is this a duplicate of #907?

[spernsteiner]

Closing as a duplicate of #907