Implemented macros in elisp compiler.

* module/language/elisp/README: Document it.
* module/language/elisp/compile-tree-il.scm: Implement defmacro and expansion.
* module/language/elisp/runtime/macro-slot.scm: New module to keep definitions.
* test-suite/Makefile.am: Add elisp-compiler.test to list of tests.
* test-suite/tests/elisp-compiler.test: Basic macro tests.

test-suite/Makefile.am

@@ -32,6 +32,7 @@ SCM_TESTS = tests/alist.test			\
 	    tests/common-list.test		\
 	    tests/continuations.test		\
 	    tests/elisp.test			\
+	    tests/elisp-compiler.text		\
 	    tests/environments.test		\
 	    tests/eval.test			\
 	    tests/exceptions.test		\

test-suite/tests/elisp-compiler.test

@@ -211,6 +211,19 @@
                 (zerop a)))))
 
 
+; Macros.
+; =======
+
+(with-test-prefix/compile "Macros"
+
+  (pass-if-equal "defmacro value" 'magic-number
+    (defmacro magic-number () 42))
+
+  (pass-if-equal "macro expansion" 1
+    (progn (defmacro take-first (a b) a)
+           (take-first 1 (/ 1 0)))))
+
+
 ; Test the built-ins.
 ; ===================