o patch by Max Nazholov:
 * more C code ported
 * missing exits fixed
 * var-modifier of shortShift128Left fixed
 * some range warnings fixed

git-svn-id: http://svn.freepascal.org/svn/fpc/trunk@24871 3ad0048d-3df7-0310-abae-a5850022a9f2
* several small errors fixed, float128<->float64 conversion works now

git-svn-id: http://svn.freepascal.org/svn/fpc/trunk@24872 3ad0048d-3df7-0310-abae-a5850022a9f2
+ added extra_param_offset constant for accessing parameters in asm routines with nostackframe

git-svn-id: http://svn.freepascal.org/svn/fpc/trunk@24873 3ad0048d-3df7-0310-abae-a5850022a9f2
+ apply extra_param_offset to all i8086 asm routines that use nostackframe

git-svn-id: http://svn.freepascal.org/svn/fpc/trunk@24874 3ad0048d-3df7-0310-abae-a5850022a9f2