Build recovery variant of the dynamic linker

In order to support shared libraries in the recovery mode, the dynamic
linker is now built with recovery_available: true option.

In addition, a few more modules (such as libasync, etc.) are also marked
as recovery_available: true as they are transitive dependencies of the
dynamic linker.

Bug: 63673171
Test: `adb reboot recovery; adb devices` shows the device ID
Test: `adb root && adb shell` and then
$ lsof -p `pidof adbd` shows that libm.so, libc.so, etc. are loaded from
the /lib directory.

Change-Id: Idd981d8cf25568a85b24032cf78e50adfd5f4a7f
diff --git a/linker/Android.bp b/linker/Android.bp
index 78d425e..fb6aa7d 100644
--- a/linker/Android.bp
+++ b/linker/Android.bp
@@ -1,6 +1,7 @@
 cc_library_static {
     name: "liblinker_malloc",
     defaults: ["linux_bionic_supported"],
+    recovery_available: true,
 
     srcs: [
         "linker_allocator.cpp",
@@ -205,6 +206,7 @@
 
     name: "linker",
     symlinks: ["linker_asan"],
+    recovery_available: true,
     multilib: {
         lib64: {
             suffix: "64",