Bump the minimum iOS version to iOS 9

Add stricter checks for getrandom()/getentropy()

configure.ac

@@ -791,7 +791,9 @@ AS_IF([test "x$EMSCRIPTEN" = "x"],[
 #endif
 ]], [[
 unsigned char buf;
-(void) getrandom((void *) &buf, 1U, 0U);
+if (&getrandom != NULL) {
+  (void) getrandom((void *) &buf, 1U, 0U);
+}
   ]])],
   [AC_MSG_RESULT(yes)
    AC_CHECK_FUNCS([getrandom])],
@@ -809,7 +811,9 @@ unsigned char buf;
 #endif
 ]], [[
 unsigned char buf;
-(void) getentropy((void *) &buf, 1U);
+if (&getentropy != NULL) {
+  (void) getentropy((void *) &buf, 1U);
+}
   ]])],
   [AC_MSG_RESULT(yes)
    AC_CHECK_FUNCS([getentropy])],

dist-build/ios.sh

@@ -17,8 +17,8 @@ export SIMULATOR32_PREFIX="$PREFIX/tmp/simulator32"
 export SIMULATOR64_PREFIX="$PREFIX/tmp/simulator64"
 export XCODEDIR=$(xcode-select -p)
 
-export IOS_SIMULATOR_VERSION_MIN=${IOS_SIMULATOR_VERSION_MIN-"8.0.0"}
-export IOS_VERSION_MIN=${IOS_VERSION_MIN-"8.0.0"}
+export IOS_SIMULATOR_VERSION_MIN=${IOS_SIMULATOR_VERSION_MIN-"9.0.0"}
+export IOS_VERSION_MIN=${IOS_VERSION_MIN-"9.0.0"}
 
 echo
 echo "Warnings related to headers being present but not usable are due to functions"