GN: Put shared libraries in outdir, not outdir/lib

build/config/gcc/BUILD.gn

 # Copyright 2014 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 # This config causes functions not to be automatically exported from shared
 # libraries. By default, all symbols are exported but this means there are
 # lots of exports that slow everything down. In general we explicitly mark
 # which functiosn we want to export from components.
 #
 # Some third_party code assumes all functions are exported so this is separated
 # into its own config so such libraries can remove this config to make symbols
 # public again.
 #
 # See http://gcc.gnu.org/wiki/Visibility
 config("symbol_visibility_hidden") {
   # Note that -fvisibility-inlines-hidden is set globally in the compiler
   # config since that can almost always be applied.
   cflags = [ "-fvisibility=hidden" ]
 }
 
 # Settings for executables and shared libraries.
 config("executable_ldconfig") {
   ldflags = [
     # Want to pass "\$". GN will re-escape as required for ninja.
-    "-Wl,-rpath=\$ORIGIN/lib/",
+    "-Wl,-rpath=\$ORIGIN/",
 
-    "-Wl,-rpath-link=lib/",
+    "-Wl,-rpath-link=",
 
     # Newer binutils don't set DT_RPATH unless you disable "new" dtags
     # and the new DT_RUNPATH doesn't work without --no-as-needed flag.
     "-Wl,--disable-new-dtags",
   ]
 
   if (is_android) {
     ldflags += [
       "-Bdynamic",
       "-Wl,-z,nocopyreloc",
     ]
   }
 }
 
 config("no_exceptions") {
   cflags_cc = [ "-fno-exceptions" ]
 }