testsuite: add bc and dc tests

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
diff --git a/testsuite/dc_divide_results.txt b/testsuite/dc_divide_results.txt
new file mode 100644
index 0000000..340ae94
--- /dev/null
+++ b/testsuite/dc_divide_results.txt
@@ -0,0 +1,32 @@
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