CVS psmith make: Fix bug#1379: don't use alloca() where it could overrun the stack size.

CVSROOT:        /cvsroot/make
Module name:    make
Changes by:     psmith  02/10/13 14:50:10

Modified files:
        .              : ChangeLog read.c commands.c 
        doc            : make.texi 
        tests          : ChangeLog 
        tests/scripts/features: targetvars 

Log message:
Fix bug#1379: don't use alloca() where it could overrun the stack size.

Implemented enhancement #1391: allow "export" in target-specific
variable definitions.

Change the Info name of the "Automatic" node to "Automatic Variables".
Add text clarifying the scope of automatic variables to that section.