[libc] [obvious] Add ctype functions to linux api.

Adds isspace, isprint, and isxdigit to Linux API to fix failed integration test.

GitOrigin-RevId: 049f6ad4f69e6b9c5df290d6f9d86c991ed4ecec
diff --git a/config/linux/api.td b/config/linux/api.td
index a57c703..71b592d 100644
--- a/config/linux/api.td
+++ b/config/linux/api.td
@@ -95,8 +95,11 @@
     "isdigit",
     "isgraph",
     "islower",
+    "isprint",
     "ispunct",
+    "isspace",
     "isupper",
+    "isxdigit",
   ];
 }