Add rustc stuff

Manishearth · Manishearth · commit 66fb0d339191 · 2020-01-01T15:23:30.000+05:30
diff --git a/Cargo.toml b/Cargo.toml
@@ -22,5 +22,9 @@ exclude = [ "target/*", "Cargo.lock", "scripts/tmp", "*.txt" ]
 [features]
 with_std = []
 default_features = ["with_std"]
+rustc-dep-of-std = ['std', 'core', 'compiler_builtins']
 
 [dependencies]
+std = { version = "1.0", package = "rustc-std-workspace-std", optional = true }
+core = { version = "1.0", package = "rustc-std-workspace-core", optional = true }
+compiler_builtins = { version = "0.1", optional = true }
