[m-rev.] for review: fix mmake rules for os,cs,css,javas

[Zoltan Somogyi]

For review by anyone.

This has been bootchecked in hlc.gc, asm_fast.gc,
csharp and java.

Zoltan.
-------------- next part --------------
A non-text attachment was scrubbed...
Name: Log.mmf
Type: application/octet-stream
Size: 3603 bytes
Desc: not available
URL: <http://lists.mercurylang.org/archives/reviews/attachments/20200411/59b74796/attachment-0002.obj>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: DIFF.mmf
Type: application/octet-stream
Size: 37729 bytes
Desc: not available
URL: <http://lists.mercurylang.org/archives/reviews/attachments/20200411/59b74796/attachment-0003.obj>