[android] the new Android overlay gets the S_IFMT definition directly from the Bionic header

Author: finagolfin

Sources/Foundation/FileManager+POSIX.swift

@@ -650,7 +650,7 @@ extension FileManager {
 
         #if !os(WASI) // WASI doesn't have ownership concept
         // Set the file permissions using fchmod() instead of when open()ing to avoid umask() issues
-        let permissions = fileInfo.st_mode & ~S_IFMT
+        let permissions = fileInfo.st_mode & ~mode_t(S_IFMT)
         guard fchmod(dstfd, permissions) == 0 else {
             throw _NSErrorWithErrno(errno, reading: false, path: dstPath,
                 extraUserInfo: extraErrorInfo(srcPath: srcPath, dstPath: dstPath, userVariant: variant))

Sources/Foundation/FileManager.swift

@@ -886,6 +886,8 @@ open class FileManager : NSObject {
         return Int(mode & ~UInt32(ucrt.S_IFMT))
 #elseif canImport(Darwin)
         return Int(mode & ~UInt32(S_IFMT))
+#elseif canImport(Android)
+        return Int(mode & ~mode_t(S_IFMT))
 #else
         return Int(mode & ~S_IFMT)
 #endif