Compiler can compile simple nested expressions and function calls.

The generated code can be called from C, and values can be passed between.
diff --git a/share/jmk/jmk.m4 b/share/jmk/jmk.m4
index cbcf3a4..b2455af 100644
--- a/share/jmk/jmk.m4
+++ b/share/jmk/jmk.m4
@@ -70,7 +70,7 @@
 	@DO_MAKE -C $2 clean')
 
 dnl lib is used to list an external dependency declared with depends()
-define(`lib', `$(jmk_lib_path_$1)/$(jmk_lib_target_$1)')
+define_blind(`lib', `$(jmk_lib_path_$1)/$(jmk_lib_target_$1)')
 
 define(`phony', `jmk_custom_phony += $1')