Upgrade indexmap to 1.5.1, now using hashbrown!

Author: cuviper

Cargo.lock

@@ -1382,9 +1382,13 @@ dependencies = [
 
 [[package]]
 name = "indexmap"
-version = "1.0.2"
+version = "1.5.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7e81a7c05f79578dbc15793d8b619db9ba32b4577003ef3af1a91c416798c58d"
+checksum = "86b45e59b16c76b11bf9738fd5d38879d3bd28ad292d7b313608becb17ae2df9"
+dependencies = [
+ "autocfg",
+ "hashbrown",
+]
 
 [[package]]
 name = "installer"

src/librustc_data_structures/Cargo.toml

@@ -11,7 +11,7 @@ doctest = false
 
 [dependencies]
 ena = "0.14"
-indexmap = "1"
+indexmap = "1.5.1"
 log = { package = "tracing", version = "0.1" }
 jobserver_crate = { version = "0.1.13", package = "jobserver" }
 lazy_static = "1"