Modifications are based on the linux kernel approach and
support two use cases:

  1) Add O= to the make command line
  'make O=/tmp/build all'

  2) Set environement variable BUILD_DIR to point to the desired location
  'export BUILD_DIR=/tmp/build'
  'make'

The second approach can also be used with a MAKEALL script
'export BUILD_DIR=/tmp/build'
'./MAKEALL'

Command line 'O=' setting overrides BUILD_DIR environent variable.

When none of the above methods is used the local build is performed and
the object files are placed in the source directory.

No commit message

Pointed out by Gerhard Jaeger, 31 Aug 2005;
cf. http://sourceware.org/ml/binutils/2005-08/msg00412.html

Patch by Yuli Barcohen, 12 Dec 2004

Minor code cleanup.