[Bug modula2/127359] building modula2 support requires bash installed in path

[gaius at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=127359

--- Comment #5 from Gaius Mulley <gaius at gcc dot gnu.org> ---
Created attachment 65607
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=65607&action=edit
Proposed fix  for makeSystem to comply with posix

Thanks for the advise and testing.

This patch invokes makeSystem with $(SHELL) and also replaces all occurrences
of echo in makeSystem with printf.

Bootstrapped on Debian amd64 and SunOS s11-sparc.cfarm 5.11.