[csmith-project/csmith] d69927: add safe_float functions

[Yang Chen <chenyang@cs.utah.edu>]

  Branch: refs/heads/floating-point
  Home:   https://github.com/csmith-project/csmith
  Commit: d69927c63879ea925de558c62c73fc296a98967d
      https://github.com/csmith-project/csmith/commit/d69927c63879ea925de558c62c73fc296a98967d
  Author: Yang Chen <chenyang@cs.utah.edu>
  Date:   2014-09-20 (Sat, 20 Sep 2014)

  Changed paths:
    M runtime/safe_math.m4
    M src/OutputMgr.cpp

  Log Message:
  -----------
  add safe_float functions

* modified versions of safe_float functions suggested by Pascal

* include float.h when --float is passed

* should have mentioned in previous commit: floating point support
is disabled by default, passing --float to enable it