integrate old m68k vfork bugfix of pre-µClibc-ng tree
integrate old m68k vfork bugfix of pre-µClibc-ng tree

foss-for-synopsys-dwc-arc-processors/uClibc,brgl/uclibc-ng,kraj/uclibc-ng,kraj/uclibc-ng,wbx-github/uclibc-ng,brgl/uclibc-ng,wbx-github/uclibc-ng,foss-for-synopsys-dwc-arc-processors/uClibc,brgl/uclibc-ng,brgl/uclibc-ng,wbx-github/uclibc-ng,kraj/uclibc-ng,kraj/uclibc-ng,foss-for-synopsys-dwc-arc-processors/uClibc,foss-for-synopsys-dwc-arc-processors/uClibc,wbx-github/uclibc-ng