samples: add Terra samples

source: https://github.com/zdevito/terra/tree/master/tests

samples/Terra/twolang.t

@@ -0,0 +1,23 @@
+
+do
+import "lib/foolang"
+a = foo bar
+import "lib/barlang"
+b = bar foo
+assert( foo bar + bar foo == 3)
+assert(a + b == 3)
+end
+
+local function failparse(str,match)
+	local r,msg = terralib.loadstring(str)
+	assert(not r)
+	local match = msg:match(match) 
+	if not match then print(msg) end
+	assert(match)
+end
+
+failparse("return (foo bar + bar foo)", "near 'bar'")
+failparse('import "lib/foolang";return (foo bar + bar foo)', "near foo")
+failparse('import "lib/foolang"; import "lib/foolang";',"entrypoint 'foo' already defined")
+
+do import "lib/foolang" end do import "lib/foolang" end