Ensure POSIX path normalizing behavior under NODERAWFS

Avoids mangling `C:/tmp` to `C:\tmp`. Should be safe, the underlying
Windows API can accept either the backslash or slash to separate
directory and file components of a path.

See: https://learn.microsoft.com/en-us/windows/win32/fileio/naming-a-file

src/library_nodepath.js

@@ -14,11 +14,11 @@
 addToLibrary({
   $PATH: {
     isAbs: (path) => nodePath['isAbsolute'](path),
-    normalize: (path) => nodePath['normalize'](path),
+    normalize: (path) => nodePath['posix']['normalize'](path),
     dirname: (path) => nodePath['dirname'](path),
     basename: (path) => nodePath['basename'](path),
-    join: (...args) => nodePath['join'](...args),
-    join2: (l, r) => nodePath['join'](l, r),
+    join: (...args) => nodePath['posix']['join'](...args),
+    join2: (l, r) => nodePath['posix']['join'](l, r),
   },
   // The FS-using parts are split out into a separate object, so simple path
   // usage does not require the FS.