ENH: add test for source_group

Alex

Tests/SourceGroups/CMakeLists.txt

@@ -0,0 +1,9 @@
+#source_group(Base             FILES main.c)
+#source_group(Base\\Sub1       FILES sub1/foo.c)
+#source_group(Base\\Sub1\\Sub2 FILES sub1/foobar.c)
+#source_group("" FILES foo.c)
+#source_group("\\" FILES bar.c)
+
+
+add_executable(SourceGroups main.c bar.c foo.c sub1/foo.c sub1/foobar.c)
+

Tests/SourceGroups/bar.c

@@ -0,0 +1,4 @@
+int barbar(void)
+{
+  return 2;
+}

Tests/SourceGroups/foo.c

@@ -0,0 +1,4 @@
+int bar(void)
+{
+  return 42;
+}

Tests/SourceGroups/main.c

@@ -0,0 +1,12 @@
+#include <stdio.h>
+
+extern int foo(void);
+extern int bar(void);
+extern int foobar(void);
+extern int barbar(void);
+
+int main()
+{
+   printf("foo: %d bar: %d foobar: %d barbar: %d\n", foo(), bar(), foobar(), barbar());
+   return 0;
+}

Tests/SourceGroups/sub1/foo.c

@@ -0,0 +1,4 @@
+int foo(void)
+{
+  return 17;
+}

Tests/SourceGroups/sub1/foobar.c

@@ -0,0 +1,4 @@
+int foobar(void)
+{
+  return 1477;
+}