…y ops

… clear rflags during enclave (re-)entry

To avoid creating memsets with outdated signature. For some reason
SROA chokes on this when using NewPM.

The new pass manager can be enabled using
-Z new-llvm-pass-manager=on.

Support new LLVM pass manager

Add support for the new LLVM pass manager behind a `-Z new-llvm-pass-manager=on` option. Both the pre-link optimization and LTO pipelines use the new pass manager. There's some bits that are not supported yet:

 * `-C passes`. NewPM requires an entirely different way of specifying custom pass pipelines. We should probably expose that functionality, but it doesn't directly map to what `-C passes` does.
 * NewPM has no support for custom inline parameters right now. We'd have to add upstream support for that first.
 * NewPM does not support PGO at O0 in LLVM 9 (which is why those tests fail with NewPM enabled). This is supported in LLVM 10.
 * NewPM does not support MergeFunctions in LLVM 9. I've landed this upstream just before the cut, so we'll be able to re-enable that with LLVM 10.

Closes rust-lang#64289.

r? @ghost

 Account for type params on method without parentheses

Account for those type parameters in the structured suggestion when forgetting to call method:

```
error[E0615]: attempted to take value of method `collect` on type `std::vec::IntoIter<_>`
  --> $DIR/method-missing-parentheses.rs:2:32
   |
LL |     let _ = vec![].into_iter().collect::<usize>;
   |                                ^^^^^^^---------
   |                                |
   |                                help: use parentheses to call the method: `collect::<usize>()`
```

…k,wesleywiser

miri: improve and simplify overflow detection

This simplifies the overflow detection for signed binary operators, and adds overflow detection to unary operators so that const-prop doesn't have to crudely hand-roll that.

It also fixes some bugs in the operator implementation that however, I think, were not observable.

r? @oli-obk @wesleywiser

Add initial debug fmt for Backtrace

Fixes the first point in rust-lang#65280

related to rust-lang#53487

…gisa

Cleanup SGX entry code

cc @aandyl

…n-DPC

Update compiler-builtins to 0.1.25

- rust-lang/compiler-builtins#340 Set probestack visibility to hidden on ELF targets

Fixes rust-lang#68794.

Tested in CI: rust-lang#69045.

r? @Mark-Simulacrum

…, r=Dylan-DPC

Minified theme check

Fixes rust-lang#69071.

r? @kinnison