some question about sodium_patches/configure.ac.patch

[yangshihao-arron]

Why is this sodium_patches/configure.ac.patch needed? Why does this patch remove these function checks?

diff --git a/configure.ac b/configure.ac
index 89c9096b..48823e8a 100644
--- a/configure.ac
+++ b/configure.ac
@@ -784,11 +784,11 @@ __sync_lock_release(&_sodium_lock);
 dnl Checks for functions and headers
 
 AC_FUNC_ALLOCA
-AS_IF([test "x$EMSCRIPTEN" = "x"],[
-  AC_CHECK_FUNCS([arc4random arc4random_buf])
-  AC_CHECK_FUNCS([mmap mlock madvise mprotect memset_s explicit_bzero nanosleep])
-])
-AC_CHECK_FUNCS([posix_memalign getpid])
+#AS_IF([test "x$EMSCRIPTEN" = "x"],[
+#  AC_CHECK_FUNCS([arc4random arc4random_buf])
+#  AC_CHECK_FUNCS([mmap mlock madvise mprotect memset_s explicit_bzero nanosleep])
+#])
+#AC_CHECK_FUNCS([posix_memalign getpid])
 
 AC_SUBST([LIBTOOL_EXTRA_FLAGS])

Can you explain it to me? I am very eager to get the answer to this question.