This appears copied from fill_buf, but the above paragraph already indicates that a lack of delimiter at the end is EOF.

…=GuillaumeGomez

add unit tests for rustdoc's processing of doctests

cc rust-lang#42018

There's a lot of things that rustdoc will do to massage doctests into something that can be compiled, and a lot of options that can be toggled to affect this. Hopefully this list of tests can show off that functionality.

The first commit is slightly unrelated but doesn't touch public functionality, because i found that if you have a manual `fn main`, it adds an extra line break at the end, whereas it would trim this extra line break if it were putting a `fn main` in automatically. That first commit makes it trim out that whitespace ahead of time.

…uietMisdreavus

Primitive docs relevant

This fixes the documentation to show the right types in the examples for many integer methods.

I need to check if the result is correct before we merge.

Remove "empty buffer" doc in read_until

This appears copied from fill_buf, but the above paragraph already indicates that a lack of delimiter at the end is EOF.

… r=QuietMisdreavus

Fix condvar example

Fixes rust-lang#48230.

r? @QuietMisdreavus

…ennytm

spelling fix in comment

r? @Manishearth

[doc] Add link to yield_now

A convenient link.

Remove unneeded string allocations

Clarify contiguity of Vec's elements.

Small doc changes for clarity.