MB-44988: Add -buildmode=exe for Windows Go module builds

Change-Id: Ia6ae564ae463b76216ffdf28f29365e96e808823
Reviewed-on: http://review.couchbase.org/c/tlm/+/148612
Reviewed-by: Isha Kandaswamy <isha@couchbase.com>
Tested-by: Chris Hillery <ceej@couchbase.com>

cmake/Modules/go-modbuild.cmake

@@ -77,14 +77,19 @@ get_filename_component(REPOSYNC "${REPOSYNC}" REALPATH)
 SET (GCFLAGS "-trimpath=${REPOSYNC}" ${GCFLAGS})
 SET (ASMFLAGS "-trimpath=${REPOSYNC}")
 
+# Work around Windows Go 1.15 link error - MB-44988
+IF (WIN32)
+  SET (_go_buildmode "-buildmode=exe")
+ENDIF ()
+
 # Execute "go build".
 SET (CMAKE_EXECUTE_PROCESS_COMMAND_ECHO STDOUT)
 EXECUTE_PROCESS (
   RESULT_VARIABLE _failure
   COMMAND "${GOEXE}" build
     "-tags=${GOTAGS}" "-gcflags=${GCFLAGS}"
     "-asmflags=${ASMFLAGS}" "-ldflags=${LDFLAGS}"
-    ${_go_debug} ${_go_race}
+    ${_go_debug} ${_go_race} ${_go_buildmode}
     -mod=readonly
     -o "${OUTPUT}"
     "${PACKAGE}")