Build with GOAMD64=v2 by default for AMD64 arch. (#13311)

Backport from main branch.
See #11715

Makefile

@@ -1,4 +1,5 @@
 GO ?= go # if using docker, should not need to be installed/linked
+GOAMD64_VERSION ?= v2 # See https://go.dev/wiki/MinimumRequirements#microarchitecture-support
 GOBINREL = build/bin
 GOBIN = $(CURDIR)/$(GOBINREL)
 UNAME = $(shell uname) # Supported: Darwin, Linux
@@ -34,6 +35,11 @@ ifeq ($(shell uname -s), Darwin)
 	endif
 endif
 
+# Configure GOAMD64 env.variable for AMD64 architecture:
+ifeq ($(shell uname -m),x86_64)
+	CPU_ARCH= GOAMD64=${GOAMD64_VERSION}
+endif
+
 # about netgo see: https://github.com/golang/go/issues/30310#issuecomment-471669125 and https://github.com/golang/go/issues/57757
 BUILD_TAGS = nosqlite,noboltdb
 
@@ -48,9 +54,9 @@ PACKAGE = github.com/erigontech/erigon
 GO_FLAGS += -trimpath -tags $(BUILD_TAGS) -buildvcs=false
 GO_FLAGS += -ldflags "-X ${PACKAGE}/params.GitCommit=${GIT_COMMIT} -X ${PACKAGE}/params.GitBranch=${GIT_BRANCH} -X ${PACKAGE}/params.GitTag=${GIT_TAG}"
 
-GOBUILD = CGO_CFLAGS="$(CGO_CFLAGS)" CGO_LDFLAGS="$(CGO_LDFLAGS)" GOPRIVATE="$(GOPRIVATE)" $(GO) build $(GO_FLAGS)
-GO_DBG_BUILD = CGO_CFLAGS="$(CGO_CFLAGS) -DMDBX_DEBUG=1" CGO_LDFLAGS="$(CGO_LDFLAGS)" GOPRIVATE="$(GOPRIVATE)" $(GO) build -tags $(BUILD_TAGS),debug -gcflags=all="-N -l"  # see delve docs
-GOTEST = CGO_CFLAGS="$(CGO_CFLAGS)" CGO_LDFLAGS="$(CGO_LDFLAGS)" GOPRIVATE="$(GOPRIVATE)" GODEBUG=cgocheck=0 $(GO) test $(GO_FLAGS) ./... -p 2
+GOBUILD = ${CPU_ARCH} CGO_CFLAGS="$(CGO_CFLAGS)" CGO_LDFLAGS="$(CGO_LDFLAGS)" GOPRIVATE="$(GOPRIVATE)" $(GO) build $(GO_FLAGS)
+GO_DBG_BUILD = ${CPU_ARCH} CGO_CFLAGS="$(CGO_CFLAGS) -DMDBX_DEBUG=1" CGO_LDFLAGS="$(CGO_LDFLAGS)" GOPRIVATE="$(GOPRIVATE)" $(GO) build -tags $(BUILD_TAGS),debug -gcflags=all="-N -l"  # see delve docs
+GOTEST = ${CPU_ARCH} CGO_CFLAGS="$(CGO_CFLAGS)" CGO_LDFLAGS="$(CGO_LDFLAGS)" GOPRIVATE="$(GOPRIVATE)" GODEBUG=cgocheck=0 $(GO) test $(GO_FLAGS) ./... -p 2
 
 default: all