Tidy up build.rs now that all xxx64 are absent for the musl target

Author: bossmc

libc-test/build.rs

@@ -3315,16 +3315,10 @@ fn test_linux(target: &str) {
             "Ioctl" if gnu => "unsigned long".to_string(),
             "Ioctl" => "int".to_string(),
 
-            t if is_union => format!("union {}", t),
-
+            // `_t` is already a typedef, no need for a keyword
             t if t.ends_with("_t") => t.to_string(),
-
-            // In MUSL `xxx64` is a typedef to `xxx`.
-            "flock64" if musl => format!("struct {}", ty),
-            "dirent64" if musl => format!("struct {}", ty),
-            "rlimit64" if musl => format!("struct {}", ty),
-            "fpos64_t" if musl => format!("struct {}", ty),
-
+            // put `union` in front of all unions:
+            t if is_union => format!("union {}", t),
             // put `struct` in front of all structs:.
             t if is_struct => format!("struct {}", t),
 
@@ -3383,7 +3377,11 @@ fn test_linux(target: &str) {
             "priority_t" if musl => true,
             "name_t" if musl => true,
 
-            _ => false,
+            t => if musl {
+                t.ends_with("64") || t.ends_with("64_t")
+            } else {
+                false
+            }
         }
     });