env: Keep -dead_strip off bare-metal links

The flavor is detected from the driver's own linker, which on macOS
is Apple's, while a bare-metal target links with LLD. LLD refuses
the option, so every link probe fails and each feature behind one
is detected as missing.

env_generic.py

@@ -288,7 +288,7 @@ def init_machine_config(machine: MachineSpec,
                 linker_flags += ["-Wl,-z,relro"]
             cxx_link_flags += ["-static-libstdc++"]
 
-        if linker_flavor == "apple":
+        if linker_flavor == "apple" and not bare:
             linker_flags += ["-Wl,-dead_strip"]
         elif not bare:
             # Would leave a link with no entry point holding on to nothing at all,