Fix the Xcode 10 support using runtime selector, the force decode feature does not process on vector image format

SDWebImage/Core/SDImageCoderHelper.m

@@ -575,6 +575,10 @@ static const CGFloat kDestSeemOverlap = 2.0f;   // the numbers of pixels to over
     if (image.sd_isAnimated) {
         return NO;
     }
+    // do not decode vector images
+    if (image.sd_isVector) {
+        return NO;
+    }
     
     return YES;
 }

SDWebImage/Core/UIImage+Metadata.m

@@ -32,25 +32,31 @@
     return (self.images != nil);
 }
 
-- (BOOL)sd_isVector {
-    if (@available(iOS 13.0, tvOS 13.0, watchOS 6.0, *)) {
-        if (self.isSymbolImage) {
-            return YES;
-        }
-    }
 #pragma clang diagnostic push
 #pragma clang diagnostic ignored "-Warc-performSelector-leaks"
+- (BOOL)sd_isVector {
+    if (@available(iOS 13.0, tvOS 13.0, watchOS 6.0, *)) {
+        // Xcode 11 supports symbol image, keep Xcode 10 compatible currently
+        SEL SymbolSelector = NSSelectorFromString(@"isSymbolImage");
+        if ([self respondsToSelector:SymbolSelector] && [self performSelector:SymbolSelector]) {
+            return YES;
+        }
+        // SVG
         SEL SVGSelector = NSSelectorFromString(@"_CGSVGDocument");
-    if ([self respondsToSelector:SVGSelector] && [self performSelector:SVGSelector] != nil) {
+        if ([self respondsToSelector:SVGSelector] && [self performSelector:SVGSelector]) {
             return YES;
         }
+    }
+    if (@available(iOS 11.0, tvOS 11.0, watchOS 4.0, *)) {
+        // PDF
         SEL PDFSelector = NSSelectorFromString(@"_CGPDFPage");
-    if ([self respondsToSelector:PDFSelector] && [self performSelector:PDFSelector] != nil) {
+        if ([self respondsToSelector:PDFSelector] && [self performSelector:PDFSelector]) {
             return YES;
         }
-#pragma clang diagnostic pop
+    }
     return NO;
 }
+#pragma clang diagnostic pop
 
 #else