Upgrade eigen to 3.4.0

Steps:
 * Removed common files between Android copy and the matching upstream copy
 * Obtained latest upstream tarball (see README.version)
 * Extracted over the directory

Bug: 148287349
Test: presubmit
Change-Id: Iee2744719075fdf000b315e973645923da766111
diff --git a/scripts/buildtests.in b/scripts/buildtests.in
index 526d5b7..ab9c18f 100755
--- a/scripts/buildtests.in
+++ b/scripts/buildtests.in
@@ -10,7 +10,7 @@
 fi
 
 TESTSLIST="@EIGEN_TESTS_LIST@"
-targets_to_make=`echo "$TESTSLIST" | egrep "$1" | xargs echo`
+targets_to_make=$(echo "$TESTSLIST" | grep -E "$1" | xargs echo)
 
 if [ -n "${EIGEN_MAKE_ARGS:+x}" ]
 then