tree ee0c23f123fdce8f175e348b79c92e5184bf1f7c
parent 271d048523b6c1b0e773d9e5cc76bbb997cc180c
parent 06acf16cdb23dad19b9cf816a55df24d4084823c
author bors <bors@rust-lang.org> 1470304897 -0700
committer GitHub <noreply@github.com> 1470304897 -0700

Auto merge of #35168 - scottcarr:deaggregation, r=nikomatsakis

[MIR] Deaggregate structs to enable further optimizations

Currently, we generate MIR like:

```
tmp0 = ...;
tmp1 = ...;
tmp3 = Foo { a: ..., b: ... };
```

This PR implements "deaggregation," i.e.:

```
tmp3.0 = ...
tmp3.1 = ...
```

Currently, the code only deaggregates structs, not enums.  My understanding is that we do not have MIR to set the discriminant of an enum.