Add polyfills for Brotli

Author: dmitrylyzo

Makefile

@@ -70,6 +70,7 @@ $(DIST_DIR)/lib/libexpat.a: build/lib/expat/configured
 	emmake make install
 
 build/lib/brotli/js/decode.js: build/lib/brotli/configured
+build/lib/brotli/js/polyfill.js: build/lib/brotli/configured
 build/lib/brotli/configured: lib/brotli $(wildcard $(BASE_DIR)build/patches/brotli/*.patch)
 	rm -rf build/lib/brotli
 	cp -r lib/brotli build/lib/brotli
@@ -325,10 +326,11 @@ dist/js/subtitles-octopus-worker.js: src/subtitles-octopus-worker.bc src/pre-wor
 		-s WASM=1 \
 		$(EMCC_COMMON_ARGS)
 
-dist/js/subtitles-octopus-worker-legacy.js: src/subtitles-octopus-worker.bc src/polyfill.js src/pre-worker.js src/SubOctpInterface.js src/post-worker.js build/lib/brotli/js/decode.js
+dist/js/subtitles-octopus-worker-legacy.js: src/subtitles-octopus-worker.bc src/polyfill.js src/pre-worker.js src/SubOctpInterface.js src/post-worker.js build/lib/brotli/js/decode.js build/lib/brotli/js/polyfill.js
 	mkdir -p dist/js
 	emcc src/subtitles-octopus-worker.bc $(OCTP_DEPS) \
 		--pre-js src/polyfill.js \
+		--pre-js build/lib/brotli/js/polyfill.js \
 		--pre-js src/pre-worker.js \
 		--pre-js build/lib/brotli/js/decode.js \
 		--post-js src/SubOctpInterface.js \

src/polyfill.js

@@ -22,6 +22,33 @@ if (!String.prototype.includes) {
     };
 }
 
+if (!ArrayBuffer.isView) {
+    var typedArrays = [
+        Int8Array,
+        Uint8Array,
+        Uint8ClampedArray,
+        Int16Array,
+        Uint16Array,
+        Int32Array,
+        Uint32Array,
+        Float32Array,
+        Float64Array
+    ];
+
+    ArrayBuffer.isView = function (obj) {
+        return obj && obj.constructor && typedArrays.indexOf(obj.constructor) !== -1;
+    };
+}
+
+if (!Int8Array.prototype.slice) {
+    Object.defineProperty(Int8Array.prototype, 'slice', {
+        value: function (begin, end)
+            {
+                return new Int8Array(this.subarray(begin, end));
+            }
+    });
+}
+
 if (!Uint8Array.prototype.slice) {
     Object.defineProperty(Uint8Array.prototype, 'slice', {
         value: function (begin, end)