Fix macOS build by adding bloaty config

This fixes the macOS host build by adding a bloaty config. However, the
bloaty config isn't quite right; followup work will be needed to decide
if it makes sense to have Mach-O bloat reports.

Change-Id: I4148c85d73a1b8dbd02b1772688259dbe59e950e
diff --git a/targets/host/macos.gni b/targets/host/macos.gni
index 8f57c3e..c1d44aa 100644
--- a/targets/host/macos.gni
+++ b/targets/host/macos.gni
@@ -18,3 +18,6 @@
   # Specifies the toolchain to use for this build.
   pw_target_toolchain = "$dir_pw_toolchain:host_clang_og"
 }
+
+pw_executable_config.bloaty_config_file =
+    get_path_info("macos.bloaty", "abspath")