PGO for libc++ am: c74f1b6bac

Original change: https://android-review.googlesource.com/c/platform/external/libcxx/+/1605138

MUST ONLY BE SUBMITTED BY AUTOMERGER

Change-Id: I0bf3f7886647f09cfd6533972154e31cfd5ca2c3
diff --git a/Android.bp b/Android.bp
index 2dbe41e..2d426ce 100644
--- a/Android.bp
+++ b/Android.bp
@@ -160,7 +160,16 @@
     whole_static_libs: ["libc++_static"],
     stl: "none",
 
+    pgo: {
+        sampling: true,
+    },
+
     target: {
+        android: {
+            pgo: {
+                profile_file: "libc++/libc++.profdata",
+            },
+        },
         darwin: {
             unexported_symbols_list: "lib/libc++unexp.exp",
             force_symbols_not_weak_list: "lib/notweak.exp",