Build fails under pypy(3) when enabling these flags.

--- llfuse-1.3.5/setup.py
+++ llfuse-1.3.5/setup.py
@@ -74,8 +74,8 @@
         long_desc = fh.read()
 
     compile_args = pkg_config('fuse', cflags=True, ldflags=False, min_ver='2.8.0')
-    compile_args += ['-DFUSE_USE_VERSION=29', '-Wall', '-Wextra', '-Wconversion',
-                     '-Wsign-compare', '-DLLFUSE_VERSION="%s"' % LLFUSE_VERSION]
+    compile_args += ['-DFUSE_USE_VERSION=29', '-Wall', '-Wextra',
+                     '-DLLFUSE_VERSION="%s"' % LLFUSE_VERSION]
 
     # We may have unused functions if we compile for older FUSE versions
     compile_args.append('-Wno-unused-function')