verilog: formatting: formatter_test: Added a test case for line continuation

Added a test case for the line continuation problem, where a line
continuation character is wrapped onto the newline causing a CHECK
failure in the tabular alignment

Signed-off-by: Jan Bylicki <jbylicki@antmicro.com>

verilog/formatting/formatter_test.cc

diff --git a/verilog/formatting/formatter_test.cc b/verilog/formatting/formatter_test.cc
index f3c3773..e617479 100644
--- a/verilog/formatting/formatter_test.cc
+++ b/verilog/formatting/formatter_test.cc
@@ -5616,6 +5616,13 @@
      "    .rst  (rst),\n"
      "    .value(value)\n"
      ");\n"},
+    {"bind foo bar baz(\\\n"
+     "`undef d\\\n"
+     "`undef d);",
+     "bind foo bar baz (\\\n"
+     "    `undef d\\\n"
+     "    `undef d\n"
+     ");\n"},
     {
         "bind expaaaaaaaaaaand_meeee looooooooong_name# ("
         ".W(W_CONST), .H(H_CONST), .D(D_CONST)  )"