RFR[9](XS): 8036614: AIX: fix adjust-mflags.sh to build with GNU Make 4.0 (adapt 8028407 for AIX)

[Volker Simonis]

Hi,

can somebody please review and sponsor the following little change
which is actually just a "copy and paste" of "8028407 adjust-mflags.sh
failed build with GNU Make 4.0 with -I<path contains j>" for the AIX
version of adjust-mflags.sh:

http://cr.openjdk.java.net/~simonis/webrevs/8036614
https://bugs.openjdk.java.net/browse/JDK-8036614

Thank you and best regards,
Volker