Rename __bionic_clone_entry to __start_thread.

This seems a bit less obscure.

Change-Id: I7dc528c253b73c861694f67556ad8f919bf92136
diff --git a/libc/arch-arm64/bionic/__bionic_clone.S b/libc/arch-arm64/bionic/__bionic_clone.S
index d3c0374..76fe24e 100644
--- a/libc/arch-arm64/bionic/__bionic_clone.S
+++ b/libc/arch-arm64/bionic/__bionic_clone.S
@@ -62,10 +62,10 @@
 .L_bc_child:
     # We're in the child now. Set the end of the frame record chain...
     mov     x29, xzr
-    # Setting x30 to 0 will make the unwinder stop at __bionic_clone_entry
+    # Setting x30 to 0 will make the unwinder stop at __start_thread
     mov     x30, xzr
-    # ...and call __bionic_clone_entry with the 'fn' and 'arg' we stored on the child stack.
+    # ...and call __start_thread with the 'fn' and 'arg' we stored on the child stack.
     ldp     x0, x1, [sp, #-16]
-    b       __bionic_clone_entry
+    b       __start_thread
 END(__bionic_clone)
 .hidden __bionic_clone