Auto merge of #4891 - MaloJaffre:compiler-docs-regression, r=alexcrichton

Try to fix a perf regression by updating log

Upgrade `log` to `0.4` in `cargo` and `cargotest`.

Cc: rust-lang/rust#47154.

Author: bors

Cargo.toml

@@ -37,7 +37,7 @@ ignore = "0.3"
 jobserver = "0.1.6"
 libc = "0.2"
 libgit2-sys = "0.6"
-log = "0.3"
+log = "0.4"
 num_cpus = "1.0"
 same-file = "1"
 scoped-tls = "0.1"

tests/cargotest/Cargo.toml

@@ -13,7 +13,7 @@ flate2 = "1.0"
 git2 = { version = "0.6", default-features = false }
 hamcrest = "=0.1.1"
 hex = "0.2"
-log = "0.3"
+log = "0.4"
 serde_json = "1.0"
 tar = { version = "0.4", default-features = false }
 url = "1.1"