Add test case for rhbz#2083296

tests/characters-in-flags/main.fmf

@@ -0,0 +1,5 @@
+summary: Test to ensure there aren't extraneous characters in build flags
+require:
+  - redhat-rpm-config
+test: ./runtest.sh
+

tests/characters-in-flags/runtest.sh

@@ -0,0 +1,7 @@
+#!/bin/bash
+
+set -ex
+
+for f in %{build_cflags} %{build_cxxflags} %{build_fflags} %{build_ldflags}; do
+  rpm --eval "$f" | grep -vP '\t'
+done