[performance] update go-structr and go-mutexes with memory usage improvements (#2909)

* update go-structr and go-mutexes with memory usage improvements

* bump to go-structr v0.8.4

vendor/github.com/dolthub/maphash/hasher.go

@@ -0,0 +1,48 @@
+// Copyright 2022 Dolthub, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package maphash
+
+import "unsafe"
+
+// Hasher hashes values of type K.
+// Uses runtime AES-based hashing.
+type Hasher[K comparable] struct {
+	hash hashfn
+	seed uintptr
+}
+
+// NewHasher creates a new Hasher[K] with a random seed.
+func NewHasher[K comparable]() Hasher[K] {
+	return Hasher[K]{
+		hash: getRuntimeHasher[K](),
+		seed: newHashSeed(),
+	}
+}
+
+// NewSeed returns a copy of |h| with a new hash seed.
+func NewSeed[K comparable](h Hasher[K]) Hasher[K] {
+	return Hasher[K]{
+		hash: h.hash,
+		seed: newHashSeed(),
+	}
+}
+
+// Hash hashes |key|.
+func (h Hasher[K]) Hash(key K) uint64 {
+	// promise to the compiler that pointer
+	// |p| does not escape the stack.
+	p := noescape(unsafe.Pointer(&key))
+	return uint64(h.hash(p, h.seed))
+}