Update Makefile build flags

For more information see: golang/go#11887

Makefile

@@ -1,9 +1,10 @@
 .DEFAULT_GOAL=test
 UNAME = $(shell uname)
 PREFIX=github.com/derekparker/delve
+FLAGS=-ldflags="-s"
 
 build:
-	go build github.com/derekparker/delve/cmd/dlv
+	go build $(FLAGS) github.com/derekparker/delve/cmd/dlv
 ifeq "$(UNAME)" "Darwin"
 ifeq "$(CERT)" ""
 	$(error You must provide a CERT env var)
@@ -12,7 +13,7 @@ endif
 endif
 
 install:
-	go install github.com/derekparker/delve/cmd/dlv
+	go install $(FLAGS) github.com/derekparker/delve/cmd/dlv
 ifeq "$(UNAME)" "Darwin"
 ifeq "$(CERT)" ""
 	$(error You must provide a CERT env var)
@@ -26,8 +27,8 @@ ifeq "$(CERT)" ""
 	$(error You must provide a CERT env var)
 endif
 	go test $(PREFIX)/terminal $(PREFIX)/dwarf/frame $(PREFIX)/dwarf/op $(PREFIX)/dwarf/util $(PREFIX)/source $(PREFIX)/dwarf/line
-	go test -c $(PREFIX)/proc && codesign -s $(CERT) ./proc.test && ./proc.test $(TESTFLAGS) && rm ./proc.test
-	go test -c $(PREFIX)/service/test && codesign -s $(CERT) ./test.test && ./test.test $(TESTFLAGS) && rm ./test.test
+	go test -c $(FLAGS) $(PREFIX)/proc && codesign -s $(CERT) ./proc.test && ./proc.test $(TESTFLAGS) && rm ./proc.test
+	go test -c  $(FLAGS) $(PREFIX)/service/test && codesign -s $(CERT) ./test.test && ./test.test $(TESTFLAGS) && rm ./test.test
 else
 	go test -v ./...
 endif
@@ -37,7 +38,7 @@ ifeq "$(UNAME)" "Darwin"
 ifeq "$(CERT)" ""
 	$(error You must provide a CERT env var)
 endif
-	go test -c $(PREFIX)/proc && codesign -s $(CERT) ./proc.test && ./proc.test -test.run $(RUN) && rm ./proc.test
+	go test -c $(FLAGS) $(PREFIX)/proc && codesign -s $(CERT) ./proc.test && ./proc.test -test.run $(RUN) && rm ./proc.test
 else
 	go test $(PREFIX) -run $(RUN)
 endif
@@ -47,7 +48,7 @@ ifeq "$(UNAME)" "Darwin"
 ifeq "$(CERT)" ""
 	$(error You must provide a CERT env var)
 endif
-	go test -c $(PREFIX)/service/test && codesign -s $(CERT) ./test.test && ./test.test -test.run $(RUN) && rm ./test.test
+	go test -c $(FLAGS) $(PREFIX)/service/test && codesign -s $(CERT) ./test.test && ./test.test -test.run $(RUN) && rm ./test.test
 else
 	go test $(PREFIX)/service/rest -run $(RUN)
 endif