Merge pull request #1417 from rust-lang/dependabot/cargo/rustc-demangle-0.1.20

Bump rustc-demangle from 0.1.19 to 0.1.20

Cargo.lock

@@ -1499,9 +1499,9 @@ dependencies = [
 
 [[package]]
 name = "rustc-demangle"
-version = "0.1.19"
+version = "0.1.20"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "410f7acf3cb3a44527c5d9546bad4bf4e6c460915d5f9f2fc524498bfe8f70ce"
+checksum = "dead70b0b5e03e9c814bcb6b01e03e68f7c57a80aa48c72ec92152ab3e818d49"
 
 [[package]]
 name = "ryu"