Stop quasi_codegen bringing in syntex stack

Unlike everything else, quasi_codegen has with-syntex as a default
feature. Probably because it breaks public API -- in our case, we'll
have to either: (a) add a non-with-syntex version of ::expand() to
quasi_codegen, or (b) adapt to it in build.rs

Author: jdub

libbindgen/Cargo.toml

@@ -20,8 +20,9 @@ clap = "2"
 shlex = "0.1"
 tests_expectations = { path = "tests/expectations" }
 
-[build-dependencies]
-quasi_codegen = "0.25"
+[build-dependencies.quasi_codegen]
+default-features = false
+version = "0.25"
 
 [dependencies]
 aster = "0.33"
@@ -55,6 +56,6 @@ default = ["logging", "syntex"]
 llvm_stable = []
 logging = ["env_logger", "log"]
 static = []
-syntex = ["syntex_syntax", "aster/with-syntex", "quasi/with-syntex"]
+syntex = ["syntex_syntax", "aster/with-syntex", "quasi/with-syntex", "quasi_codegen/with-syntex"]
 # This feature only exists for CI -- don't use it!
 _docs = []