* toplev.c (set_float_handler): Make static.
* toplev.h: Don't prototype set_float_handler.
* simplify-rtx.c: Don't include setjmp.h.
(simplify_unary_real, simplify_binary_real, simplify_binary_is2orm1):
New functions.
(simplify_unary_operation, simplify_binary_operation): Use them,
via do_float_handler.
* fold-const.c: Don't include setjmp.h.
(exact_real_inverse_1): New function.
(exact_real_inverse): Use it, via do_float_handler.
* varasm.c: Don't include setjmp.h.
(assemble_real_1): New function.
(assemble_real): Use it, via do_float_handler.
Call internal_error if we get a trap here.