feat: initial tracing support (#1623)

vendor/github.com/grpc-ecosystem/grpc-gateway/v2/utilities/pattern.go

@@ -0,0 +1,22 @@
+package utilities
+
+// An OpCode is a opcode of compiled path patterns.
+type OpCode int
+
+// These constants are the valid values of OpCode.
+const (
+	// OpNop does nothing
+	OpNop = OpCode(iota)
+	// OpPush pushes a component to stack
+	OpPush
+	// OpLitPush pushes a component to stack if it matches to the literal
+	OpLitPush
+	// OpPushM concatenates the remaining components and pushes it to stack
+	OpPushM
+	// OpConcatN pops N items from stack, concatenates them and pushes it back to stack
+	OpConcatN
+	// OpCapture pops an item and binds it to the variable
+	OpCapture
+	// OpEnd is the least positive invalid opcode.
+	OpEnd
+)