0.7.5.10:

0.7.5.10:
	Begin to fix floating point exceptions on PPC
	... write an os_context_fp_control function
	... use it in CONTEXT-FLOATING-POINT-MODES
	(this, unlike on the SPARC and Alpha ports, doesn't fix all the
		normal-user problems.  After the first return from the Lisp
		debugger on the PPC, the FLOATING-POINT-MODES are (almost)
		cleared, which means that the second bad floating point
		operation is not trapped).