Improve gnulib in gdb's guess work, gettimeofday() works in uClibcm promise.

This patch helps building x86_64-unknown-linux-uclibc toolchains, the final
gdb-native step otherwise fails when linking the libinproctrace.so

Signed-off-by: Joachim Nilsson <troglobit@gmail.com>
Signed-off-by: Alexey Neyman <stilor@att.net>

diff -urpN gdb-7.12.orig/gdb/gnulib/configure gdb-7.12/gdb/gnulib/configure
--- gdb-7.12.orig/gdb/gnulib/configure	2017-01-13 13:42:11.773027566 -0800
+++ gdb-7.12/gdb/gnulib/configure	2017-01-13 13:44:32.518082618 -0800
@@ -13522,6 +13522,7 @@ else
       case "$host_os" in
                 # Guess all is fine on glibc systems.
         *-gnu*) gl_cv_func_gettimeofday_clobber="guessing no" ;;
+        *-uclibc*) gl_cv_func_gettimeofday_clobber="guessing no" ;;
                 # If we don't know, assume the worst.
         *)      gl_cv_func_gettimeofday_clobber="guessing yes" ;;
       esac
diff -urpN gdb-7.12.orig/gdb/gnulib/import/m4/gettimeofday.m4 gdb-7.12/gdb/gnulib/import/m4/gettimeofday.m4
--- gdb-7.12.orig/gdb/gnulib/import/m4/gettimeofday.m4	2017-01-13 13:42:11.777027595 -0800
+++ gdb-7.12/gdb/gnulib/import/m4/gettimeofday.m4	2017-01-13 13:43:55.781797640 -0800
@@ -111,6 +111,7 @@ AC_DEFUN([gl_FUNC_GETTIMEOFDAY_CLOBBER],
       case "$host_os" in
                 # Guess all is fine on glibc systems.
         *-gnu*) gl_cv_func_gettimeofday_clobber="guessing no" ;;
+        *-uclibc*) gl_cv_func_gettimeofday_clobber="guessing no" ;;
                 # If we don't know, assume the worst.
         *)      gl_cv_func_gettimeofday_clobber="guessing yes" ;;
       esac