Rollup merge of #36180 - frewsxcv:patch-33, r=alexcrichton

Transition Travis CI to use rustbuild.

Author: Jonathan Turner

.travis.yml

@@ -15,9 +15,9 @@ before_install:
 script:
   - docker run -v `pwd`:/build rust
     sh -c "
-      ./configure --llvm-root=/usr/lib/llvm-3.7 &&
+      ./configure --enable-rustbuild --llvm-root=/usr/lib/llvm-3.7 &&
       make tidy &&
-      make check-notidy -j4
+      make check -j4
     "
 
 # Real testing happens on http://buildbot.rust-lang.org/

src/bootstrap/compile.rs

@@ -203,6 +203,10 @@ pub fn rustc<'a>(build: &'a Build, target: &str, compiler: &Compiler<'a>) {
         cargo.env("LLVM_RUSTLLVM", "1");
     }
     cargo.env("LLVM_CONFIG", build.llvm_config(target));
+    let target_config = build.config.target_config.get(target);
+    if let Some(s) = target_config.and_then(|c| c.llvm_config.as_ref()) {
+        cargo.env("CFG_LLVM_ROOT", s);
+    }
     if build.config.llvm_static_stdcpp {
         cargo.env("LLVM_STATIC_STDCPP",
                   compiler_file(build.cxx(target), "libstdc++.a"));