Fix subnormal number parsing on mingw32
Fix subnormal number parsing on mingw32

Patch by Blanca Elio Rosario.

Mephistophiles/jansson,markalanj/jansson,AmesianX/jansson,Mephistophiles/jansson,markalanj/jansson,akheron/jansson,bstarynk/jansson,AmesianX/jansson,wirebirdlabs/featherweight-jansson,npmccallum/jansson,markalanj/jansson,npmccallum/jansson,wirebirdlabs/featherweight-jansson,bstarynk/jansson,akheron/jansson,akheron/jansson,bstarynk/jansson