Revert "Auto merge of rust-lang#43059 - Mark-Simulacrum:rustbuild-2.0, r=alexcrichton"

This reverts commit 8d22af8, reversing
changes made to f8d485f.

Author: Mark-Simulacrum

src/Cargo.lock

@@ -33,11 +33,8 @@ build_helper = { path = "../build_helper" }
 cmake = "0.1.23"
 filetime = "0.1"
 num_cpus = "1.0"
+toml = "0.1"
 getopts = "0.2"
+rustc-serialize = "0.3"
 gcc = "0.3.50"
 libc = "0.2"
-serde = "1.0.8"
-serde_derive = "1.0.8"
-serde_json = "1.0.2"
-toml = "0.4"
-lazy_static = "0.2"