add pkgconfig file generation
update sets for ncurses pkgconfig change.
Remove additional files generated during ld.so build on make clean.
We don't have to pass the syscall number using the swi instruction.

This is part of AAPCS.  Our kernel already supports this.

ok drahn@
Properly align the stacks for 8-byte alignment. (AAPCS)

ok drahn@
Fix whitespaces.

ok drahn@
Implement fenv for vfp in libm.

ok drahn@
Don't need softfloat on eabi.

ok drahn@
Properly add target and build ABI to clang Makefile.

ok drahn@
Take care of the new target triples in Makefile.cross.

On eabi, our standard target triple will stay arm-unknown-bitrig0.1.
Though, to tell our compilers to target the correct cpu and abi.
For this, we will have to target armv7-unknown-bitrig0.1-gnueabihf.

Diff from drahn@
ok drahn@