arch: add softfp support

Some architectures support a mixed hard/soft floating point, where
the compiler emits hardware floating point instructions, but passes
the operands in core (aka integer) registers.

For example, ARM supports this mode (to come in the next changeset).

Add support for softfp cross compilers to the GCC and GLIBC
configuration. Needed for Ubuntu and other distros that are softfp.

Signed-off-by: Michael Hope <michael.hope@linaro.org>
[yann.morin.1998@anciens.enib.fr: split the original patch]
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>

 --- glibc-2_9.orig/nptl/init.c	2007-10-15 22:25:25.000000000 +0200

 +++ glibc-2_9/nptl/init.c	2010-08-18 10:46:06.109098646 +0200

 @@ -236,7 +236,7 @@

  /* This can be set by the debugger before initialization is complete.  */

 -static bool __nptl_initial_report_events;

 +static bool __nptl_initial_report_events __attribute_used__;

  void

  __pthread_initialize_minimal_internal (void)