Provides a Solaris implementation of the floating point exception handler.
Will not send upstream.

--- IexMath/IexMathFpu.cpp	2014-08-10 14:23:56.000000000 +1000
+++ IexMath/IexMathFpu.cpp	2016-11-09 11:22:07.833814195 +1000
@@ -271,19 +271,37 @@
 // it's passed to the signal handler by the kernel.  Use
 // the kernel's version of the ucontext to get it, see
 // <asm/sigcontext.h>
 //

+#if defined(__sun)
+#include <sys/ucontext.h>
+#include <sys/regset.h>
+#else
 #include <asm/sigcontext.h>
+#endif
 
 inline void
 restoreControlRegs (const ucontext_t & ucon, bool clearExceptions)
 {
-    setCw ((ucon.uc_mcontext.fpregs->cw & cwRestoreMask) | cwRestoreVal);
     
+#if !defined(__sun)
+    setCw ((ucon.uc_mcontext.fpregs->cw & cwRestoreMask) | cwRestoreVal);
     _fpstate * kfp = reinterpret_cast<_fpstate *> (ucon.uc_mcontext.fpregs);
     setMxcsr (kfp->magic == 0 ? kfp->mxcsr : 0, clearExceptions);
+
+#else
+    setCw ((ucon.uc_mcontext.fpregs.fp_reg_set.fpchip_state.cw & cwRestoreMask) | cwRestoreVal);
+    fpregset_t kfp = ucon.uc_mcontext.fpregs;
+    uint32_t f_mxcsr = kfp.fp_reg_set.fpchip_state.mxcsr;
+    uint32_t f_xstatus = kfp.fp_reg_set.fpchip_state.xstatus;
+
+    // http://lxr.free-electrons.com/source/arch/x86/include/uapi/asm/sigcontext.h#L7
+    // was very helpful in figuring out this next line.
+    setMxcsr (f_xstatus == 0 ? f_mxcsr : 0, clearExceptions);
+#endif
+
 }
 
 #endif
 
 } // namespace FpuControl
@@ -452,20 +470,26 @@
         return;
     }
 }
 
 
+#if defined(__sun)
+#define	SA_NOMASK	SA_NODEFER
+#endif
+
 void
 setFpExceptionHandler (FpExceptionHandler handler)
 {
     if (fpeHandler == 0)
     {
 	struct sigaction action;
 	sigemptyset (&action.sa_mask);
 	action.sa_flags = SA_SIGINFO | SA_NOMASK;
 	action.sa_sigaction = (void (*) (int, siginfo_t *, void *)) catchSigFpe;
+#if !defined(__sun)
 	action.sa_restorer = 0;
+#endif
 
 	sigaction (SIGFPE, &action, 0);
     }
 
     fpeHandler = handler;