Allow customized output for make build/{tctl,tsh}

Makefile

@@ -356,15 +356,16 @@ binaries:
 # * Build will rely on go build internal caching https://golang.org/doc/go1.10 at all times
 # * Manual change detection was broken on a large dependency tree
 # If you are considering changing this behavior, please consult with dev team first
-#
+
 # NOTE: Any changes to the `tctl` build here must be copied to `build.assets/windows/build.ps1`
 # until we can use this Makefile for native Windows builds.
 .PHONY: $(BUILDDIR)/tctl
+$(BUILDDIR)/tctl: OUT ?= $@
 $(BUILDDIR)/tctl:
 	@if [[ "$(OS)" != "windows" && -z "$(LIBFIDO2_BUILD_TAG)" ]]; then \
 		echo 'Warning: Building tctl without libfido2. Install libfido2 to have access to MFA.' >&2; \
 	fi
-	GOOS=$(OS) GOARCH=$(ARCH) $(CGOFLAG) go build -tags "$(PAM_TAG) $(FIPS_TAG) $(LIBFIDO2_BUILD_TAG) $(PIV_BUILD_TAG) $(KUSTOMIZE_NO_DYNAMIC_PLUGIN)" -o $(BUILDDIR)/tctl $(BUILDFLAGS) ./tool/tctl
+	GOOS=$(OS) GOARCH=$(ARCH) $(CGOFLAG) go build -tags "$(PAM_TAG) $(FIPS_TAG) $(LIBFIDO2_BUILD_TAG) $(PIV_BUILD_TAG) $(KUSTOMIZE_NO_DYNAMIC_PLUGIN)" -o $(OUT) $(BUILDFLAGS) ./tool/tctl
 
 .PHONY: $(BUILDDIR)/teleport
 # Appending new conditional settings for community build type
@@ -381,11 +382,12 @@ $(BUILDDIR)/teleport: ensure-webassets bpf-bytecode rdpclient
 .PHONY: $(BUILDDIR)/tsh
 $(BUILDDIR)/tsh: KUBECTL_VERSION ?= $(shell go run ./build.assets/kubectl-version/main.go)
 $(BUILDDIR)/tsh: KUBECTL_SETVERSION ?= -X k8s.io/component-base/version.gitVersion=$(KUBECTL_VERSION)
+$(BUILDDIR)/tsh: OUT ?= $@
 $(BUILDDIR)/tsh:
 	@if [[ "$(OS)" != "windows" && -z "$(LIBFIDO2_BUILD_TAG)" ]]; then \
 		echo 'Warning: Building tsh without libfido2. Install libfido2 to have access to MFA.' >&2; \
 	fi
-	GOOS=$(OS) GOARCH=$(ARCH) $(CGOFLAG_TSH) go build -tags "$(FIPS_TAG) $(LIBFIDO2_BUILD_TAG) $(TOUCHID_TAG) $(PIV_BUILD_TAG) $(VNETDAEMON_TAG) $(KUSTOMIZE_NO_DYNAMIC_PLUGIN)" -o $(BUILDDIR)/tsh $(BUILDFLAGS) ./tool/tsh
+	GOOS=$(OS) GOARCH=$(ARCH) $(CGOFLAG_TSH) go build -tags "$(FIPS_TAG) $(LIBFIDO2_BUILD_TAG) $(TOUCHID_TAG) $(PIV_BUILD_TAG) $(VNETDAEMON_TAG) $(KUSTOMIZE_NO_DYNAMIC_PLUGIN)" -o $(OUT) $(BUILDFLAGS) ./tool/tsh
 
 .PHONY: $(BUILDDIR)/tbot
 # tbot is CGO-less by default except on Windows because lib/client/terminal/ wants CGO on this OS