Merge pull request #982 from rust-lang/dependabot/cargo/once_cell-1.5.2

Cargo.lock

@@ -1031,9 +1031,9 @@ dependencies = [
 
 [[package]]
 name = "once_cell"
-version = "1.5.1"
+version = "1.5.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f53cef67919d7d247eb9a2f128ca9e522789967ef1eb4ccd8c71a95a8aedf596"
+checksum = "13bd41f508810a131401606d54ac32a467c97172d74ba7662562ebba5ad07fa0"
 
 [[package]]
 name = "opaque-debug"