Revert vendor directory to support old golang (GOPATH mode)

gomodule is still in progress to migrate for now, hence multus
team decide to keep vendor directory to support build without
gomodule.

vendor/github.com/json-iterator/go/iter_skip_sloppy.go

@@ -0,0 +1,144 @@
+//+build jsoniter_sloppy
+
+package jsoniter
+
+// sloppy but faster implementation, do not validate the input json
+
+func (iter *Iterator) skipNumber() {
+	for {
+		for i := iter.head; i < iter.tail; i++ {
+			c := iter.buf[i]
+			switch c {
+			case ' ', '\n', '\r', '\t', ',', '}', ']':
+				iter.head = i
+				return
+			}
+		}
+		if !iter.loadMore() {
+			return
+		}
+	}
+}
+
+func (iter *Iterator) skipArray() {
+	level := 1
+	for {
+		for i := iter.head; i < iter.tail; i++ {
+			switch iter.buf[i] {
+			case '"': // If inside string, skip it
+				iter.head = i + 1
+				iter.skipString()
+				i = iter.head - 1 // it will be i++ soon
+			case '[': // If open symbol, increase level
+				level++
+			case ']': // If close symbol, increase level
+				level--
+
+				// If we have returned to the original level, we're done
+				if level == 0 {
+					iter.head = i + 1
+					return
+				}
+			}
+		}
+		if !iter.loadMore() {
+			iter.ReportError("skipObject", "incomplete array")
+			return
+		}
+	}
+}
+
+func (iter *Iterator) skipObject() {
+	level := 1
+	for {
+		for i := iter.head; i < iter.tail; i++ {
+			switch iter.buf[i] {
+			case '"': // If inside string, skip it
+				iter.head = i + 1
+				iter.skipString()
+				i = iter.head - 1 // it will be i++ soon
+			case '{': // If open symbol, increase level
+				level++
+			case '}': // If close symbol, increase level
+				level--
+
+				// If we have returned to the original level, we're done
+				if level == 0 {
+					iter.head = i + 1
+					return
+				}
+			}
+		}
+		if !iter.loadMore() {
+			iter.ReportError("skipObject", "incomplete object")
+			return
+		}
+	}
+}
+
+func (iter *Iterator) skipString() {
+	for {
+		end, escaped := iter.findStringEnd()
+		if end == -1 {
+			if !iter.loadMore() {
+				iter.ReportError("skipString", "incomplete string")
+				return
+			}
+			if escaped {
+				iter.head = 1 // skip the first char as last char read is \
+			}
+		} else {
+			iter.head = end
+			return
+		}
+	}
+}
+
+// adapted from: https://github.com/buger/jsonparser/blob/master/parser.go
+// Tries to find the end of string
+// Support if string contains escaped quote symbols.
+func (iter *Iterator) findStringEnd() (int, bool) {
+	escaped := false
+	for i := iter.head; i < iter.tail; i++ {
+		c := iter.buf[i]
+		if c == '"' {
+			if !escaped {
+				return i + 1, false
+			}
+			j := i - 1
+			for {
+				if j < iter.head || iter.buf[j] != '\\' {
+					// even number of backslashes
+					// either end of buffer, or " found
+					return i + 1, true
+				}
+				j--
+				if j < iter.head || iter.buf[j] != '\\' {
+					// odd number of backslashes
+					// it is \" or \\\"
+					break
+				}
+				j--
+			}
+		} else if c == '\\' {
+			escaped = true
+		}
+	}
+	j := iter.tail - 1
+	for {
+		if j < iter.head || iter.buf[j] != '\\' {
+			// even number of backslashes
+			// either end of buffer, or " found
+			return -1, false // do not end with \
+		}
+		j--
+		if j < iter.head || iter.buf[j] != '\\' {
+			// odd number of backslashes
+			// it is \" or \\\"
+			break
+		}
+		j--
+
+	}
+	return -1, true // end with \
+}