RFR: JDK-8199682 Clean up building the saproc library

[Magnus Ihse Bursie]

The saproc library has historically been built in quite odd ways on 
almost all platforms. When the old build system was converted, this was 
not changed.

However, now the time has come to streamline this and build this library 
just as any other.

The most visible change, perhaps, is that the library is now named 
saproc on all platforms, even Windows. Other changes include:
* Don't set flags that is already set by the default flags.
* Don't set flags that do not have anny effect.
* Don't subst away the WIN32_LEAN_AND_MEAN definition, it's perfectly 
okay to have it.
* Don't set CXX linker on solaris -- this was not needed so no reason to 
do it.
* Cleaned up some old hooks for closed code that is no longer needed.

I have verified this using COMPARE_BUILD. This shows only the expected 
differences:
* On all platforms: class file changes for WindbgDebuggerLocal.java.
* On solaris: some minor symbol differences, since the linker now uses C 
framework functions instead of C++. (And with symbol changes always 
comes disasm changes.)
* On linux: a binary difference for libsaproc.so, but no 
size/symbol/deps/disasm change.
* On macosx: no changes at all.
* On windows: sawindbg.dll is renamed to saproc.dll. When I made a 
manual comparison between the two files, I found no significant differences.

Bug: https://bugs.openjdk.java.net/browse/JDK-8199682
WebRev: 
http://cr.openjdk.java.net/~ihse/JDK-8199682-clean-up-saproc/webrev.01

/Magnus