compiletest: use std::path::absolute instead of hand-rolling

Author: jieyouxu

Diff for: src/tools/compiletest/src/lib.rs

@@ -237,10 +237,6 @@ pub fn parse_config(args: Vec<String>) -> Config {
         }
     }
 
-    fn make_absolute(path: PathBuf) -> PathBuf {
-        if path.is_relative() { env::current_dir().unwrap().join(path) } else { path }
-    }
-
     let target = opt_str2(matches.opt_str("target"));
     let android_cross_path = opt_path(matches, "android-cross-path");
     let (cdb, cdb_version) = debuggers::analyze_cdb(matches.opt_str("cdb"), &target);
@@ -329,8 +325,8 @@ pub fn parse_config(args: Vec<String>) -> Config {
         fail_fast: matches.opt_present("fail-fast")
             || env::var_os("RUSTC_TEST_FAIL_FAST").is_some(),
 
-        compile_lib_path: make_absolute(opt_path(matches, "compile-lib-path")),
-        run_lib_path: make_absolute(opt_path(matches, "run-lib-path")),
+        compile_lib_path: std::path::absolute(opt_path(matches, "compile-lib-path")),
+        run_lib_path: std::path::absolute(opt_path(matches, "run-lib-path")),
         rustc_path: opt_path(matches, "rustc-path"),
         cargo_path: matches.opt_str("cargo-path").map(PathBuf::from),
         stage0_rustc_path: matches.opt_str("stage0-rustc-path").map(PathBuf::from),