To define OPENSSL_NO_FP_API for all MSDOS type targets was unfair
against DJGPP, and much more restricted than previous definitions.

e_os2.h

diff --git a/e_os2.h b/e_os2.h
index 80ec03e..4fd6c62 100644
--- a/e_os2.h
+++ b/e_os2.h
@@ -200,8 +200,10 @@
 
 
 /* Specials for I/O an exit */
-#ifdef OPENSSL_SYS_MSDOS
+#ifdef OPENSSL_SYS_WIN16
 # define OPENSSL_NO_FP_API
+#endif
+#ifdef OPENSSL_SYS_MSDOS
 # define OPENSSL_UNISTD_IO <io.h>
 # define OPENSSL_DECLARE_EXIT extern void exit(int);
 #else