Add libraryDependencyTag to track dependencies on static and shared libraries

dependencyTag uses a set of predefined tags to identify different types
of dependencies.  There are already multiple bits of metadata stored
in the dependency tag (Library, Shared, ReexportFlags), and supporting
them all requires a combinatorial explosion of predefined tags and
causes issues when using equality comparisons if a new bit of metadata
is added.

Add a new libraryDependencyTag type that will contain the metadata
bits, and replace the quality comparisons with checks on the metadata
bits.

There are 5 TODOs where modifying the checks identified problems with
the existing checks.  These were left in place to produce identical
build output and will be fixed separately.

Bug: 162437057
Test: no change to build.ninja or {Android,make_vars,late}-${TARGET_PRODUCT}.mk
Change-Id: I72d4207dcf381c07c92e00e5a03968ebb5ed8d30
diff --git a/cc/sanitize.go b/cc/sanitize.go
index 300bc8f..33e4a4a 100644
--- a/cc/sanitize.go
+++ b/cc/sanitize.go
@@ -714,8 +714,14 @@
 }
 
 func isSanitizableDependencyTag(tag blueprint.DependencyTag) bool {
-	t, ok := tag.(DependencyTag)
-	return ok && t.Library || t == reuseObjTag || t == objDepTag
+	switch t := tag.(type) {
+	case dependencyTag:
+		return t == reuseObjTag || t == objDepTag
+	case libraryDependencyTag:
+		return true
+	default:
+		return false
+	}
 }
 
 // Propagate sanitizer requirements down from binaries
@@ -957,10 +963,11 @@
 				}
 
 				// static executable gets static runtime libs
+				depTag := libraryDependencyTag{Kind: staticLibraryDependency}
 				mctx.AddFarVariationDependencies(append(mctx.Target().Variations(), []blueprint.Variation{
 					{Mutator: "link", Variation: "static"},
 					c.ImageVariation(),
-				}...), StaticDepTag, deps...)
+				}...), depTag, deps...)
 			} else if !c.static() && !c.header() {
 				// If we're using snapshots and in vendor, redirect to snapshot whenever possible
 				if c.VndkVersion() == mctx.DeviceConfig().VndkVersion() {
@@ -971,10 +978,11 @@
 				}
 
 				// dynamic executable and shared libs get shared runtime libs
+				depTag := libraryDependencyTag{Kind: sharedLibraryDependency, Order: earlyLibraryDependency}
 				mctx.AddFarVariationDependencies(append(mctx.Target().Variations(), []blueprint.Variation{
 					{Mutator: "link", Variation: "shared"},
 					c.ImageVariation(),
-				}...), earlySharedDepTag, runtimeLibrary)
+				}...), depTag, runtimeLibrary)
 			}
 			// static lib does not have dependency to the runtime library. The
 			// dependency will be added to the executables or shared libs using