compile all of base/; some arbitrary changes; more "fixes" to `link'

* module/language/scheme/translate.scm (lookup-transformer): When
  expanding syncase macros, use the eval closure from the ghil-env.
  Probably doesn't make any difference whatsoever.

* module/system/base/Makefile.am (SOURCES): Compile pmatch.scm, now that
  it works :-))

* module/system/base/compile.scm (compile-in): Compile inside a
  save-module-excursion, so that side effects of evaluation don't leak
  out.

* module/system/base/pmatch.scm: Change from :use-syntax/:export-syntax
  to simply :use-modules/:export. Also probably has no effect.

* module/system/il/ghil.scm (fix-ghil-mod!): Suppress warnings resulting
  from compilation of define-module.

* src/vm_loader.c (link): So, referencing variables defined but not
  exported from the current module didn't work. Fixed that, but it's
  hacky. There are still some uncaught cases.

module/system/base/compile.scm

@@ -115,20 +115,22 @@
   (call-with-input-file file (language-read-file lang)))
 
 (define (compile-in x e lang . opts)
-  (catch 'result
-    (lambda ()
-      ;; expand
-      (set! x ((language-expander lang) x e))
-      (if (memq :e opts) (throw 'result x))
-      ;; translate
-      (set! x ((language-translator lang) x e))
-      (if (memq :t opts) (throw 'result x))
-      ;; compile
-      (set! x (apply compile x e opts))
-      (if (memq :c opts) (throw 'result x))
-      ;; assemble
-      (apply assemble x e opts))
-    (lambda (key val) val)))
+  (save-module-excursion
+   (lambda ()
+     (catch 'result
+      (lambda ()
+        ;; expand
+        (set! x ((language-expander lang) x e))
+        (if (memq :e opts) (throw 'result x))
+        ;; translate
+        (set! x ((language-translator lang) x e))
+        (if (memq :t opts) (throw 'result x))
+        ;; compile
+        (set! x (apply compile x e opts))
+        (if (memq :c opts) (throw 'result x))
+        ;; assemble
+        (apply assemble x e opts))
+      (lambda (key val) val)))))
 
 ;;;
 ;;;