create base/fenv.c to standerdize fenv across platforms. It's a c file and not a cpp file because c99
(which defines fenv) doesn't necessarily extend to c++ and it is a problem with solaris. If really
desired this could wrap the ieeefp interface found in bsd* as well, but I see no need at the moment.

src/arch/alpha/isa/fp.isa:
src/arch/sparc/isa/formats/basic.isa:
use m5_fesetround()/m5_fegetround() istead of fenv interface directly
src/arch/sparc/isa/includes.isa:
use base/fenv instead of fenv directly
src/base/SConscript:
add fenv to sconscript
src/base/fenv.hh:
src/base/random.cc:
m5 implementation to standerdize fenv across platforms.

Updated Authors from bk prs info

New directory structure:
- simulator source now in 'src' subdirectory
- imported files from 'ext' repository
- support building in arbitrary places, including
outside of the source tree. See comment at top
of SConstruct file for more details.
Regression tests are temporarily disabled; that
syetem needs more extensive revisions.

SConstruct:
Update for new directory structure.
Modify to support build trees that are not subdirectories
of the source tree. See comment at top of file for
more details.
Regression tests are temporarily disabled.
src/arch/SConscript:
src/arch/isa_parser.py:
src/python/SConscript:
Update for new directory structure.