cc: export Stripper struct

The cc stripping logic can be reused for Rust. Export the Stripper
structure for that purpose. Extract the strip-related flags from
builderFlags into StripFlags. Add the method flagsToStripFlags
(similarly to flagsToBuilderFlags).

Add the helper method disableStripping on libraryDecorator.

Test: m
Bug: 153430439
Change-Id: I11aef1abb8d498a4c1672500a7398279edf7f548
diff --git a/cc/prebuilt.go b/cc/prebuilt.go
index baf43ce..3af65d6 100644
--- a/cc/prebuilt.go
+++ b/cc/prebuilt.go
@@ -125,9 +125,10 @@
 			outputFile := android.PathForModuleOut(ctx, libName)
 			var implicits android.Paths
 
-			if p.needsStrip(ctx) {
+			if p.stripper.NeedsStrip(ctx) {
+				stripFlags := flagsToStripFlags(flags)
 				stripped := android.PathForModuleOut(ctx, "stripped", libName)
-				p.stripExecutableOrSharedLib(ctx, in, stripped, builderFlags)
+				p.stripper.StripExecutableOrSharedLib(ctx, in, stripped, stripFlags)
 				in = stripped
 			}
 
@@ -331,16 +332,16 @@
 	flags Flags, deps PathDeps, objs Objects) android.Path {
 	// TODO(ccross): verify shared library dependencies
 	if len(p.properties.Srcs) > 0 {
-		builderFlags := flagsToBuilderFlags(flags)
+		stripFlags := flagsToStripFlags(flags)
 
 		fileName := p.getStem(ctx) + flags.Toolchain.ExecutableSuffix()
 		in := p.Prebuilt.SingleSourcePath(ctx)
 
 		p.unstrippedOutputFile = in
 
-		if p.needsStrip(ctx) {
+		if p.stripper.NeedsStrip(ctx) {
 			stripped := android.PathForModuleOut(ctx, "stripped", fileName)
-			p.stripExecutableOrSharedLib(ctx, in, stripped, builderFlags)
+			p.stripper.StripExecutableOrSharedLib(ctx, in, stripped, stripFlags)
 			in = stripped
 		}