* gnu/packages/patches/valgrind-glibc.patch: s/2.18/2.19/.
* gnu/packages/patches/valgrind-glibc.patch: update it.
* gnu/packages/valgrind.scm, gnu/packages/patches/valgrind-glibc.patch: New files. * gnu-system.am (GNU_SYSTEM_MODULES): Add valgrind.scm. (dist_patch_DATA): Add valgrind-glibc.patch.