Ansi C Police

fftw is supposed to compile with c89/c90.  Restore this property
so that I can test with gcc -ansi.

This change may seem needlessly reactionary, but in the last release I
accidentally inserted an assertion before a declaration and I broke
the Visual Studio build, so we must be careful not to use C99
constructs.

There are a few non-ANSI function calls in tests, e.g. isnan(),
drand48(), snprintf().  Since nobody has complained about those in
years, I am leaving them alone.

kernel/cycle.h

@@ -223,7 +223,7 @@ typedef unsigned long long ticks;
 static __inline__ ticks getticks(void)
 {
      unsigned a, d; 
-     asm volatile("rdtsc" : "=a" (a), "=d" (d)); 
+     __asm__ __volatile__ ("rdtsc" : "=a" (a), "=d" (d)); 
      return ((ticks)a) | (((ticks)d) << 32); 
 }