Move PackageIdentifier to cmdline

This is necessary to have TargetResolver depend on it without making it depend
on the packages target. First step of #389.

--
MOS_MIGRATED_REVID=101790345
diff --git a/src/main/java/com/google/devtools/build/lib/skyframe/GlobValue.java b/src/main/java/com/google/devtools/build/lib/skyframe/GlobValue.java
index c93370c..f1db29b 100644
--- a/src/main/java/com/google/devtools/build/lib/skyframe/GlobValue.java
+++ b/src/main/java/com/google/devtools/build/lib/skyframe/GlobValue.java
@@ -14,12 +14,12 @@
 package com.google.devtools.build.lib.skyframe;
 
 import com.google.common.base.Preconditions;
+import com.google.devtools.build.lib.cmdline.PackageIdentifier;
 import com.google.devtools.build.lib.collect.nestedset.NestedSet;
 import com.google.devtools.build.lib.collect.nestedset.NestedSetBuilder;
 import com.google.devtools.build.lib.collect.nestedset.Order;
 import com.google.devtools.build.lib.concurrent.ThreadSafety.Immutable;
 import com.google.devtools.build.lib.concurrent.ThreadSafety.ThreadSafe;
-import com.google.devtools.build.lib.packages.PackageIdentifier;
 import com.google.devtools.build.lib.vfs.PathFragment;
 import com.google.devtools.build.lib.vfs.UnixGlob;
 import com.google.devtools.build.skyframe.SkyKey;