Revert^2 "Switch platform-NDK unwinder to LLVM libunwind.a prebuilt"

This reverts commit 74bdc28817.

Bug: http://b/153025717
Test: treehugger
Change-Id: I11410f213732c52755a3bd3d4d0769570354484e

cc/stl.go

@@ -188,12 +188,7 @@ func (stl *stl) deps(ctx BaseModuleContext, deps Deps) Deps {
 		if needsLibAndroidSupport(ctx) {
 			deps.StaticLibs = append(deps.StaticLibs, "ndk_libandroid_support")
 		}
-		// TODO: Switch the NDK over to the LLVM unwinder for non-arm32 architectures.
-		if ctx.Arch().ArchType == android.Arm {
-			deps.StaticLibs = append(deps.StaticLibs, "ndk_libunwind")
-		} else {
-			deps.StaticLibs = append(deps.StaticLibs, "libgcc_stripped")
-		}
+		deps.StaticLibs = append(deps.StaticLibs, "ndk_libunwind")
 	default:
 		panic(fmt.Errorf("Unknown stl: %q", stl.Properties.SelectedStl))
 	}