Fix _ocamlver() for Pacman 5.1.0

Makepkg apparently now parses the PKGBUILDS in advance and doesn't like
seeing empty pkgvers for dependencies. With our split package for the
OCaml bindings we declare a dependency on the installed OCaml version,
so that upgrades to OCaml wouldn't break the bindings. When llvm-ocaml
is built, OCaml is installed and thus _ocamlver() returns a valid
version. But now we also need to return a valid version before OCaml is
installed. It doesn't need to be meaningful, as it'll get updated again
to the real version if package_llvm-ocaml-svn() gets to be run later.

Author: kerberizer

PKGBUILD

@@ -77,7 +77,8 @@ _py_sitepkg_dir="/usr/lib/python2.7/site-packages"
 # Determine the installed OCaml package version
 # Arguments: NONE
 _ocamlver() {
-    pacman -Q ocaml | awk '{ print $2 }' | cut -d - -f 1 | cut -d . -f 1,2,3
+    { pacman -Q ocaml 2>/dev/null || echo 'ocaml 0.0.0-0' ;} \
+            | awk '{ print $2 }' | cut -d - -f 1 | cut -d . -f 1,2,3
 }
 
 # Fix the Python interpreter path in .py files to point to python2