Rollup merge of #66834 - infinity0:master, r=Mark-Simulacrum

rustbuild fixes

When upgrading Debian's rustc to 1.38 I needed these patches:

(1) In order to cross-compile rustc 1.38 and take it through the full rustbuild process including install, I needed the first patch.

(2) In order to build rustc 1.38 using rustc 1.38 itself I need to set --cap-lints warn, otherwise I get this error:

~~~~
error: unnecessary `unsafe` block
   --> src/bootstrap/builder.rs:148:19
    |
148 |             name: unsafe { ::std::intrinsics::type_name::<S>() },
    |                   ^^^^^^ unnecessary `unsafe` block
    |
note: lint level defined here
   --> src/bootstrap/lib.rs:107:9
    |
107 | #![deny(warnings, rust_2018_idioms, unused_lifetimes)]
    |         ^^^^^^^^
    = note: `#[deny(unused_unsafe)]` implied by `#[deny(warnings)]`

error: aborting due to previous error

error: could not compile `bootstrap`.

~~~~

In order to set --cap-lints warn however, I need bootstrap.py not to clobber RUSTFLAGS. (This worked previously, not sure if it was broken intentionally but we would like support for it.)

0 files changed, 0 insertions, 0 deletions