rt: don't save and restore xmm/regs in __morestack.
checkpoint
Fix a bug where calling p.destroy() on the result of calling
start_program(...) would cause a segfault when p went
out of scope due to out_file/err_file being closed twice.
Update doc-comments to reflect the current year and trait
names now being capitalized.
Change the behaviour of core::run::Program.destroy to
forcibly terminate the program (as suggested in issue #5632)
Feed enum field offsets to type vistors.
Export adt::trans_get_discr abstractly to the type visitor.
When repr'ing an enum value, assert that it matched some variant.
Make the enum visit callback generator more readable
Make intrinsic::Opaque more opaque
Add #[start] attribute to define a new entry point function
Change tests to use new error message
Reason about nested free variables that appear in a function
signature.  In a nutshell, the idea is to (1) report an error if, for
a region pointer `'a T`, the lifetime `'a` is longer than any
lifetimes that appear in `T` (in other words, if a borrowed pointer
outlives any portion of its contents) and then (2) use this to assume
that in a function like `fn(self: &'a &'b T)`, the relationship `'a <=
'b` holds. This is needed for #5656.  Fixes #5728.
Add debug info for boxes
Add debug info for vectors
Add debug info for bare_fn type
Prevent debug info generation of zero-span nodes

If a node has a (0, 0) span, it was not in the source, so debug symbols should not be generated for it.
Add debug info test for boxes
Add debug info test for vectors
Add examples for Rng functions.