convert Library builder specs to integration tests

spec/build_tests_spec.rb

@@ -960,4 +960,13 @@ EOF
       expect(result.stderr).to match /unknown input file type: "foo.xyz"/
     end
   end
+
+  context "Library builder" do
+    it "allows overriding ARCMD construction variable" do
+      test_dir("library")
+      result = run_test(rsconsfile: "override_arcmd.rb")
+      expect(result.stderr).to eq ""
+      expect(lines(result.stdout)).to include "ar rcf lib.a one.o three.o two.o"
+    end
+  end
 end

spec/rscons/builders/library_spec.rb

@@ -1,28 +0,0 @@
-module Rscons
-  module Builders
-    describe Library do
-      let(:env) {Environment.new}
-      subject {Library.new}
-
-      it "supports overriding AR construction variable" do
-        expect(subject).to receive(:standard_build).with("AR prog.a", "prog.a", ["sp-ar", "rcs", "prog.a", "prog.o"], ["prog.o"], env, :cache)
-        subject.run(
-          target: "prog.a",
-          sources: ["prog.o"],
-          cache: :cache,
-          env: env,
-          vars: {"AR" => "sp-ar"})
-      end
-
-      it "supports overriding ARCMD construction variable" do
-        expect(subject).to receive(:standard_build).with("AR prog.a", "prog.a", ["special", "AR!", "prog.o"], ["prog.o"], env, :cache)
-        subject.run(
-          target: "prog.a",
-          sources: ["prog.o"],
-          cache: :cache,
-          env: env,
-          vars: {"ARCMD" => ["special", "AR!", "${_SOURCES}"]})
-      end
-    end
-  end
-end