Consider target_family as pal

Currently tidy does not consider code in target_family as
platform-specific. I think this is erroneous and should be fixed.

Signed-off-by: Ayush Singh <ayushsingh1325@gmail.com>

Author: Ayush1325

src/tools/tidy/src/pal.rs

@@ -62,6 +62,8 @@ const EXCEPTION_PATHS: &[&str] = &[
     "library/std/src/panic.rs",   // fuchsia-specific panic backtrace handling
     "library/std/src/personality.rs",
     "library/std/src/personality/",
+    "library/std/src/thread/mod.rs",
+    "library/std/src/thread/local.rs",
 ];
 
 pub fn check(path: &Path, bad: &mut bool) {
@@ -128,6 +130,7 @@ fn check_cfgs(
             || cfg.contains("target_env")
             || cfg.contains("target_abi")
             || cfg.contains("target_vendor")
+            || cfg.contains("target_family")
             || cfg.contains("unix")
             || cfg.contains("windows");