RFR: JDK-8248610 Clean up handling of Windows RC files

Wed Jul 1 00:27:10 UTC 2020

The logic for handling .rc files in Windows has been quite messy. The 
variable RCFLAGS was incorrectly named RC_FLAGS. In it, we mixed 
tool-specific values with defines needed by version.rc. The contents of 
version.rc was needlessly copied in several places, with some variation. 
Some of the "special" rc files that added to functionality provided by 
the "global" version.rc was in need of some love.

Bug: https://bugs.openjdk.java.net/browse/JDK-8248610
WebRev: 
http://cr.openjdk.java.net/~ihse/JDK-8248610-clean-up-RCFLAGS/webrev.01

/Magnus