Add finite limit to virtual memory used when checking msolve

Rather than allowing unlimited virtual memory, we increase the upper
bound to 1.5 GB, which should still allow all the tests to pass.

M2/libraries/msolve/Makefile.in

@@ -6,7 +6,7 @@ LICENSEFILES = README.md COPYING
 
 PRECONFIGURE = ./autogen.sh
 
-VLIMIT = unlimited
+VLIMIT = 1500000
 
 include ../Makefile.library
 Makefile: @srcdir@/Makefile.in ; cd ../.. && ./config.status libraries/msolve/Makefile