Fix function type-equivalence requiring same param names, addresses #957

testing/btest/Baseline/language.func-assignment/out

@@ -0,0 +1,4 @@
+Brogrammers, like bowties, are cool. Brogrammers, like bowties, are cool. Brogrammers, like bowties, are cool.
+Brogrammers, like bowties, are cool. Brogrammers, like bowties, are cool.
+BROGRAMMERS, LIKE BOWTIES, ARE COOL.
+BROGRAMMERS, LIKE BOWTIES, ARE COOL.

testing/btest/language/func-assignment.bro

@@ -0,0 +1,39 @@
+# @TEST-EXEC: bro -b %INPUT >out
+# @TEST-EXEC: btest-diff out
+
+function double_string(s: string): string
+	{
+	return string_cat(s, " ", s);
+	}
+
+function triple_string(str: string): string
+	{
+	return string_cat(str, " ", str, " ", str);
+	}
+
+type sample_function: record {
+	s: string;
+	f: function(str: string): string;
+};
+
+event bro_init()
+	{
+	local test_sf: sample_function;
+	test_sf$s = "Brogrammers, like bowties, are cool.";
+
+	test_sf$f = triple_string;
+	print test_sf$f(test_sf$s);
+
+	test_sf$f = double_string;
+	print test_sf$f(test_sf$s);
+
+	# Works as expected
+	test_sf$f = function(str: string): string
+		{ return to_upper(str); };
+	print test_sf$f(test_sf$s);
+
+	# Func arg names shouldn't factor in to the type check.
+	test_sf$f = function(s: string): string
+		{ return to_upper(s); };
+	print test_sf$f(test_sf$s);
+	}