Duplicate tests that are run twice as both C and C++ tests to fix parallel make: empty

Examples/test-suite/common.mk

@@ -603,7 +603,7 @@ C_TEST_CASES += \
 	char_constant \
 	const_const \
 	constant_expr \
-	empty \
+	empty_c \
 	enums \
 	enum_forward \
 	enum_macro \

Examples/test-suite/empty_c.i

@@ -0,0 +1 @@
+%module empty_c

Examples/test-suite/go/empty_c_runme.go

@@ -0,0 +1,6 @@
+package main
+
+import _ "./empty_c"
+
+func main() {
+}

Examples/test-suite/javascript/empty_c_runme.js

@@ -0,0 +1 @@
+var empty_c = require("empty_c");

Examples/test-suite/octave/empty_c_runme.m

@@ -0,0 +1,2 @@
+empty_c
+

Examples/test-suite/python/empty_c_runme.py

@@ -0,0 +1 @@
+import empty_c

Examples/test-suite/scilab/empty_c_runme.sci

@@ -0,0 +1,3 @@
+exec("swigtest.start", -1);
+
+exec("swigtest.quit", -1);