Change rmake and doc-test to support TESTNAME

Closes #11288
Closes #11222
std: adjust requested stack size for thread-local storage.

If there is a lot of data in thread-local storage some implementations
of pthreads (e.g. glibc) fail if you don't request a stack large enough
-- by adjusting for the minimum size we guarantee that our stacks are
always large enough. Issue #6233.
Don't allow single-variant enums to be dereferenced. #6246

I'm not sure if this was even intentional at this point.
auto merge of #11284 : huonw/rust/issue-6233, r=alexcrichton

If there is a lot of data in thread-local storage some implementations
of pthreads (e.g. glibc) fail if you don't request a stack large enough
-- by adjusting for the minimum size we guarantee that our stacks are
always large enough. Issue #6233.
Don't allow newtype structs to be dereferenced. #6246
rustc: Add error about obsolete struct deref
doc: Fix tutorial for struct deref
doc: Fix an inexplicable error in a tutorial example

This code was wrong but apparently worked before removing struct
deref. I don't know why.
auto merge of #11188 : brson/rust/noderef, r=brson

This removes the feature where newtype structs can be dereferenced like pointers, and likewise where certain enums can be dereferenced (which I imagine nobody realized still existed). This ad-hoc behavior is to be replaced by a more general overloadable dereference trait in the future.

I've been nursing this patch for two months and think it's about rebased up to master.

@nikomatsakis this makes a bunch of your type checking code noticeably uglier.
auto merge of #11290 : alexcrichton/rust/testname, r=brson

Closes #11288
Closes #11222