[committed] Fix missing include in check_effective_target_fd_truncate

[Marek Polacek]

In -std=gnu11 as a default mode many Fortran tests ended up as
UNSUPPORTED, because check_effective_target_fd_truncate routine
was missing the string.h header (it uses strncmp) hence it failed.

Applying to trunk.

2014-10-07  Marek Polacek  <pola...@redhat.com>

        * lib/target-supports.exp (check_effective_target_fd_truncate):
        Include <string.h>.

diff --git gcc/testsuite/lib/target-supports.exp 
gcc/testsuite/lib/target-supports.exp
index 77e45cb..2144683 100644
--- gcc/testsuite/lib/target-supports.exp
+++ gcc/testsuite/lib/target-supports.exp
@@ -5284,6 +5284,7 @@ proc check_effective_target_fd_truncate { } {
        #include <unistd.h>
        #include <stdio.h>
        #include <stdlib.h>
+       #include <string.h>
        int main ()
        {
          FILE *f = fopen ("tst.tmp", "wb");

        Marek