rust: add ccToolchain to Module

The cc toolchain information is required when using cc.Stripper.
Move to a Module method to avoid importing the cc package everywhere.

Test: m nothing
Bug: 153430439
Change-Id: I497dcdff4e767ecb8b8688c73cf88850c302683d

rust/rust.go

@@ -23,6 +23,7 @@ import (
 
 	"android/soong/android"
 	"android/soong/cc"
+	cc_config "android/soong/cc/config"
 	"android/soong/rust/config"
 )
 
@@ -656,6 +657,10 @@ func (mod *Module) toolchain(ctx android.BaseModuleContext) config.Toolchain {
 	return mod.cachedToolchain
 }
 
+func (mod *Module) ccToolchain(ctx android.BaseModuleContext) cc_config.Toolchain {
+	return cc_config.FindToolchain(ctx.Os(), ctx.Arch())
+}
+
 func (d *Defaults) GenerateAndroidBuildActions(ctx android.ModuleContext) {
 }