hdf5_ep

[svn-r10962] Purpose: Solve the Difference of Compiler and Library

Description: In this data conversion test, from floating number to floating number,
when the source is bigger than the destination, overflow may happen.  The library
assign INFINITY while compiler's behavior is undefined.  A compiler like SGI assigns
the maximal value for the destination.

Solution: When this situation occurs, simply check if the destination is INFINITY
instead of comparing values.

Platforms tested: modi4 and h5committest.