- fix generation of sysnum.h for parallel builds, second take.   Revert r21503 and redo more cleanly.
- fix generation of sysnum.h for parallel builds, second take.
  Revert r21503 and redo more cleanly.

foss-xtensa/uClibc,wbx-github/uclibc-ng,majek/uclibc-vx32,hjl-tools/uClibc,waweber/uclibc-clang,gittup/uClibc,OpenInkpot-archive/iplinux-uclibc,mephi42/uClibc,kraj/uclibc-ng,m-labs/uclibc-lm32,groundwater/uClibc,kraj/uClibc,ffainelli/uClibc,wbx-github/uclibc-ng,brgl/uclibc-ng,brgl/uclibc-ng,mephi42/uClibc,hjl-tools/uClibc,foss-xtensa/uClibc,waweber/uclibc-clang,OpenInkpot-archive/iplinux-uclibc,wbx-github/uclibc-ng,ffainelli/uClibc,kraj/uclibc-ng,wbx-github/uclibc-ng,majek/uclibc-vx32,waweber/uclibc-clang,kraj/uClibc,ffainelli/uClibc,skristiansson/uClibc-or1k,kraj/uClibc,ndmsystems/uClibc,majek/uclibc-vx32,foss-for-synopsys-dwc-arc-processors/uClibc,ysat0/uClibc,ysat0/uClibc,czankel/xtensa-uclibc,skristiansson/uClibc-or1k,groundwater/uClibc,ddcc/klee-uclibc-0.9.33.2,ffainelli/uClibc,hwoarang/uClibc,kraj/uClibc,waweber/uclibc-clang,hjl-tools/uClibc,czankel/xtensa-uclibc,gittup/uClibc,kraj/uclibc-ng,majek/uclibc-vx32,czankel/xtensa-uclibc,ddcc/klee-uclibc-0.9.33.2,foss-for-synopsys-dwc-arc-processors/uClibc,gittup/uClibc,ysat0/uClibc,ndmsystems/uClibc,hwoarang/uClibc,groundwater/uClibc,mephi42/uClibc,brgl/uclibc-ng,ddcc/klee-uclibc-0.9.33.2,m-labs/uclibc-lm32,mephi42/uClibc,foss-for-synopsys-dwc-arc-processors/uClibc,ysat0/uClibc,foss-xtensa/uClibc,foss-for-synopsys-dwc-arc-processors/uClibc,OpenInkpot-archive/iplinux-uclibc,ffainelli/uClibc,hjl-tools/uClibc,atgreen/uClibc-moxie,skristiansson/uClibc-or1k,ddcc/klee-uclibc-0.9.33.2,atgreen/uClibc-moxie,atgreen/uClibc-moxie,ndmsystems/uClibc,m-labs/uclibc-lm32,groundwater/uClibc,hwoarang/uClibc,kraj/uclibc-ng,hjl-tools/uClibc,foss-xtensa/uClibc,groundwater/uClibc,OpenInkpot-archive/iplinux-uclibc,m-labs/uclibc-lm32,atgreen/uClibc-moxie,hwoarang/uClibc,ndmsystems/uClibc,gittup/uClibc,czankel/xtensa-uclibc,brgl/uclibc-ng,skristiansson/uClibc-or1k