Simplify early compilation interface

[cjgillot]

• separate resolver creation and AST configuration.
• bundle lowering with global_ctxt creation.

[rust-highfive]

r? @jackh726

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[cjgillot]

@bors try @rust-timer queue

[rust-timer]

Awaiting bors try build completion.

@rustbot label: +S-waiting-on-perf

[bors]

⌛ Trying commit cc326346b3ec0657b164407f5bf89f8ee2a43e96 with merge 4559bbd8a4a11c3b934fc8dcde6319d259f6396b...

[bors]

☀️ Try build successful - checks-actions
Build commit: 4559bbd8a4a11c3b934fc8dcde6319d259f6396b (4559bbd8a4a11c3b934fc8dcde6319d259f6396b)

[rust-timer]

Queued 4559bbd8a4a11c3b934fc8dcde6319d259f6396b with parent 75d1500, future comparison URL.

[rust-timer]

Finished benchmarking try commit (4559bbd8a4a11c3b934fc8dcde6319d259f6396b): comparison url.

Benchmarking this pull request likely means that it is perf-sensitive, so we're automatically marking it as not fit for rolling up. Please note that if the perf results are neutral, you should likely undo the rollup=never given below by specifying rollup- to bors.

Importantly, though, if the results of this run are non-neutral do not roll this PR up -- it will mask other regressions or improvements in the roll up.

@bors rollup=never
@rustbot label: +S-waiting-on-review -S-waiting-on-perf

[petrochenkov]

Perhaps Zoxc had something in mind when making lower_to_hir individually available, but if no tools use it right now, then it seems fine to remove.

[petrochenkov]

@bors r+

[bors]

📌 Commit f698774 has been approved by petrochenkov

[bors]

⌛ Testing commit f698774 with merge e6f450b...

[bors]

☀️ Test successful - checks-actions
Approved by: petrochenkov
Pushing e6f450b to master...