Remove unused stdint.h check

https://bugs.chromium.org/p/webm/issues/detail?id=1119

Change-Id: I88891d9f0be29ac6f845d2b470e5735dad16e693

configure

@@ -260,7 +260,6 @@ ARCH_EXT_LIST="
 HAVE_LIST="
     ${ARCH_EXT_LIST}
     vpx_ports
-    stdint_h
     pthread_h
     sys_mman_h
     unistd_h
@@ -545,14 +544,11 @@ process_detect() {
             # Specialize windows and POSIX environments.
             case $toolchain in
                 *-win*-*)
-                    case $header-$toolchain in
-                        stdint*-gcc) true;;
-                        *) false;;
-                    esac && enable_feature $var
-                    ;;
+                    # Don't check for any headers in Windows builds.
+                    false
+                ;;
                 *)
                     case $header in
-                        stdint.h) true;;
                         pthread.h) true;;
                         sys/mman.h) true;;
                         unistd.h) true;;
@@ -570,7 +566,6 @@ process_detect() {
 int main(void) {return 0;}
 EOF
     # check system headers
-    check_header stdint.h
     check_header pthread.h
     check_header sys/mman.h
     check_header unistd.h # for sysconf(3) and friends.