RFR: JDK-8210941 Stop filtering out -xregs=no%appl for libsunec

[Magnus Ihse Bursie]

We have been filtering out the -xregs=no%appl when compiling libsunec 
for sparc. This is just an remnant of the old build system, where this 
were not properly set. (The recommendation is to use it for dlls.) To 
mimic the old behavior, we chose to filter it out when converting the 
old build system. But there's really no point in keeping it.

Bug: https://bugs.openjdk.java.net/browse/JDK-8210941
WebRev: 
http://cr.openjdk.java.net/~ihse/JDK-8210941-stop-filter-xregs-no-appl-on-libsunec/webrev.01

/Magnus