Add symlinks to third_party/ and tools/ to base_workspace

While attempting to clean up the Bazel examples, I noticed that the example
tests don't actually work because they expect a third_party directory. We could
link third_party/ from the top-level bazel directory, but then we'd have
crossing symlinks (base_workspace/tools->tools and
third_party->base_workspace/third_party). Linking everything in one direction
seemed like a better option, but alternative suggestions are welcome.

--
MOS_MIGRATED_REVID=86703332

.gitignore

@@ -1,8 +1,8 @@
 /output/
 /bazel-*
 /fromhost/
-/base_workspace/tools/jdk/jdk
-/base_workspace/tools/java/ijar
-/base_workspace/tools/java/JavaBuilder_deploy.jar
-/base_workspace/tools/java/SingleJar_deploy.jar
-/tools
+/base_workspace/tools/
+/tools/jdk/jdk
+/tools/java/ijar
+/tools/java/JavaBuilder_deploy.jar
+/tools/java/SingleJar_deploy.jar

compile.sh

@@ -64,8 +64,9 @@ function log() {
   fi
 }
 
-# Create a tools symlink so we can run the Bazel bootstrap.
-rm -f tools && ln -s base_workspace/tools tools
+# Create symlinks so we can use tools from the base_workspace.
+rm -f base_workspace/tools && ln -s $(pwd)/tools base_workspace/tools
+rm -f base_workspace/third_party && ln -s $(pwd)/third_party base_workspace/third_party
 
 mkdir -p fromhost
 cat << EOF > fromhost/BUILD
@@ -181,7 +182,6 @@ esac
 test -z "$JAVA_HOME" && fail "JDK not found, please set \$JAVA_HOME."
 rm -f tools/jdk/jdk && ln -s "${JAVA_HOME}" tools/jdk/jdk
 
-
 JAVAC="${JAVA_HOME}/bin/javac"
 
 [[ -x $JAVAC ]] \

src/test/java/com/google/devtools/build/lib/testutil/FoundationTestCase.java

@@ -91,7 +91,7 @@ private void copySkylarkFilesIfExist() throws IOException {
     scratchFile(rootDirectory.getRelative("devtools/blaze/rules/BUILD").getPathString());
     scratchFile(rootDirectory.getRelative("rules/BUILD").getPathString());
     copySkylarkFilesIfExist("devtools/blaze/rules/staging", "devtools/blaze/rules/staging");
-    copySkylarkFilesIfExist("devtools/blaze/bazel/base_workspace/tools/build_rules", "rules");
+    copySkylarkFilesIfExist("devtools/blaze/bazel/tools/build_rules", "rules");
   }
 
   private void copySkylarkFilesIfExist(String from, String to) throws IOException {

base_workspace/tools/cpp/BUILD → tools/cpp/BUILD

@@ -21,8 +21,8 @@ filegroup(
 filegroup(
     name = "toolchain",
     srcs = [
-        ":cc-compiler-local",
         ":cc-compiler-darwin",
+        ":cc-compiler-local",
         ":empty",
     ],
 )