added readme

test/readme.txt

@@ -0,0 +1,16 @@
+This directory contains test code for automatic regression testing of the CC65
+compiler.
+
+
+/val  - the bulk of tests are contained here, individual tests should exit with
+        an exit code of EXIT_SUCCESS when they pass, or EXIT_FAILURE on error
+
+/ref  - these tests produce output that must be compared with reference output
+
+/err  - contains tests that MUST NOT compile
+
+/misc - a few tests that need special care of some sort
+
+
+to run the tests use "make clean all" in this (top) directory, the makefile
+should exit with no error.

test/todo

@@ -0,0 +1,10 @@
+
+- the tests in ./misc need special care
+
+- check all tests in ./ref and make them return their results as exit code
+
+- in ./val use some other tool than "diff" for comparing the results
+
+- fixup makefiles to use "del" instead of "rm -f" on windows
+
+- reduce usage of "common.h" to a minimum