Disable has_thread_local due to weird issues in some programs

For example, in the following issue the `thread_info` thread-local is
not correctly initialized in debug builds:
https://github.com/Meziu/ctru-rs/issues/60

compiler/rustc_target/src/spec/armv6k_nintendo_3ds.rs

@@ -37,7 +37,8 @@ pub fn target() -> Target {
             pre_link_args,
             exe_suffix: ".elf".into(),
             no_default_libraries: false,
-            has_thread_local: true,
+            // There are some issues in debug builds with this enabled in certain programs.
+            has_thread_local: false,
             ..Default::default()
         },
     }