Removes files from //build that we don't need

build/git-hooks/pre-commit

-#!/bin/sh
-
-submodule_diff() {
-  if test -n "$2"; then
-    git diff-tree -r --ignore-submodules=dirty "$1" "$2" | grep -e '^:160000' -e '^:...... 160000' | xargs
-  else
-    git diff-index --cached --ignore-submodules=dirty "$1" | grep -e '^:160000' -e '^:...... 160000' | xargs
-  fi
-}
-
-if git rev-parse --verify --quiet --no-revs MERGE_HEAD; then
-  merge_base=$(git merge-base HEAD MERGE_HEAD)
-  if test -z "$(submodule_diff $merge_base HEAD)"; then
-    # Most up-to-date submodules are in MERGE_HEAD.
-    head_ref=MERGE_HEAD
-  else
-    # Most up-to-date submodules are in HEAD.
-    head_ref=HEAD
-  fi
-else
-  # No merge in progress. Submodules must match HEAD.
-  head_ref=HEAD
-fi
-
-submods=$(submodule_diff $head_ref)
-if test "$submods"; then
-  echo "You are trying to commit changes to the following submodules:" 1>&2
-  echo 1>&2
-  echo $submods | cut -d ' ' -f 6 | sed 's/^/  /g' 1>&2
-  cat <<EOF 1>&2
-
-Submodule commits are not allowed.  Please run:
-
-  git status --ignore-submodules=dirty
-
-and/or:
-
-  git diff-index --cached --ignore-submodules=dirty HEAD
-
-... to see what's in your index.
-
-If you're really and truly trying to roll the version of a submodule, you should
-commit the new version to DEPS, instead.
-EOF
-  exit 1
-fi
-
-gitmodules_diff() {
-  git diff-index --cached "$1" .gitmodules
-}
-
-if [ "$(git ls-files .gitmodules)" ] && [ "$(gitmodules_diff $head_ref)" ]; then
-  cat <<EOF 1>&2
-You are trying to commit a change to .gitmodules.  That is not allowed.
-To make changes to submodule names/paths, edit DEPS.
-EOF
-  exit 1
-fi
-
-exit 0