[kaffe] MIN_VALUE of java.lang.Double

[Ito Kazumitsu]

Kaffe's MIN_VALUE of java.lang.Double is

   4.9406564584124654418e-324

but can't this be changed to 5e-324?  This is the
MIN_VALUE of GNU Classpath's java.lang.Double.

My machine's poor strtod converts 4.9406564584124654418e-324 to
zero,  so make failes while compiling java/lang/Double.c.
My machine's poor strtod seems to recognize 5e-324 as a non-zero
value.