rustc: Remove DepGraph handling from rustc_metadata

[alexcrichton]

This should now be entirely tracked through queries, so no need to have a
DepGraph in the CStore object any more!

cc #44390

[alexcrichton]

r? @michaelwoerister

[rust-highfive]

r? @nikomatsakis

(rust_highfive has picked a reviewer for you, use r? to override)

[Mark-Simulacrum]

@bors p=1 (This feels like it may have performance impact).

[michaelwoerister]

@bors r+

Thanks, Alex! It's way better this way :)

[bors]

📌 Commit 304c8de has been approved by michaelwoerister

[kennytm]

@bors p=0

Could not compile rustdoc on PR CI. Please reset the priority to p=1 after that is fixed.

[00:33:42] error[E0061]: this function takes 1 parameter but 2 parameters were supplied
[00:33:42]    --> /checkout/src/librustdoc/core.rs:149:38
[00:33:42]     |
[00:33:42] 149 |     let cstore = Rc::new(CStore::new(&dep_graph, box rustc_trans::LlvmMetadataLoader));
[00:33:42]     |                                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected 1 parameter
[00:33:42] 
[00:33:44] error[E0061]: this function takes 1 parameter but 2 parameters were supplied
[00:33:44]   --> /checkout/src/librustdoc/test.rs:88:38
[00:33:44]    |
[00:33:44] 88 |     let cstore = Rc::new(CStore::new(&dep_graph, box rustc_trans::LlvmMetadataLoader));
[00:33:44]    |                                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected 1 parameter
[00:33:44] 
[00:33:44] error[E0061]: this function takes 1 parameter but 2 parameters were supplied
[00:33:44]    --> /checkout/src/librustdoc/test.rs:241:38
[00:33:44]     |
[00:33:44] 241 |     let cstore = Rc::new(CStore::new(&dep_graph, box rustc_trans::LlvmMetadataLoader));
[00:33:44]     |                                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected 1 parameter
[00:33:44] 
[00:33:44] error: aborting due to 3 previous errors
[00:33:44] 
[00:33:44] error: Could not compile `rustdoc`.

[alexcrichton]

@bors: r=michaelwoerister

[bors]

📌 Commit fdbbd58 has been approved by michaelwoerister

[kennytm]

@bors p=1

[alexcrichton]

@bors: r=michaelwoerister

[bors]

📌 Commit 28e2cd4 has been approved by michaelwoerister

[bors]

⌛ Testing commit 28e2cd403912e548edf0cfcc1ad28a2fa934c1d7 with merge 9026e62408040fca85697aad1d3c07cd560bd296...

[bors]

💔 Test failed - status-travis

[alexcrichton]

@bors: r=michaelwoerister

[bors]

📌 Commit d724d03 has been approved by michaelwoerister

[bors]

⌛ Testing commit d724d03 with merge 34035d2...

[bors]

☀️ Test successful - status-appveyor, status-travis
Approved by: michaelwoerister
Pushing 34035d2 to master...