fix resolving c symbols in C

internal/shop.cm

@@ -72,11 +72,19 @@ function get_packages_dir() {
 
 // Get the core directory (in the global shop)
 var core_package = 'core'
+var _core_realpath = null
 
 Shop.get_core_dir = function() {
   return get_packages_dir() + '/' + core_package
 }
 
+function is_core_dir(dir) {
+  if (dir == 'core') return true
+  if (_core_realpath == null)
+    _core_realpath = fd.realpath(Shop.get_core_dir()) || false
+  return _core_realpath && dir == _core_realpath
+}
+
 // Get the reports directory (in the global shop)
 Shop.get_reports_dir = function() {
   return global_shop_path + '/reports'
@@ -818,9 +826,9 @@ function resolve_path(path, ctx)
   ctx_path = ctx_dir + '/' + path
 
   if (fd.is_file(ctx_path)) {
-    is_core = (ctx == 'core') || (ctx_dir == Shop.get_core_dir())
+    is_core = (ctx == 'core') || is_core_dir(ctx_dir)
     scope = is_core ? SCOPE_CORE : SCOPE_LOCAL
-    return {path: ctx_path, scope: scope, pkg: ctx}
+    return {path: ctx_path, scope: scope, pkg: is_core ? 'core' : ctx}
   }
 
   if (is_internal_path(path))
@@ -973,7 +981,8 @@ function try_dylib_symbol(sym, pkg, file_stem) {
 
 // Resolve a C symbol by searching:
 // At each scope: check build-cache dylib first, then internal (static)
-function resolve_c_symbol(path, package_context) {
+function resolve_c_symbol(path, _pkg_ctx) {
+  var package_context = is_core_dir(_pkg_ctx) ? 'core' : _pkg_ctx
   var explicit = split_explicit_package_import(path)
   var sym = null
   var loader = null
@@ -1284,7 +1293,8 @@ function get_module(path, package_context) {
   return execute_module(info)
 }
 
-Shop.use = function use(path, package_context) {
+Shop.use = function use(path, _pkg_ctx) {
+  var package_context = is_core_dir(_pkg_ctx) ? 'core' : _pkg_ctx
   // Check for embedded module (static builds)
   var embed_key = 'embedded:' + path
   var embedded = null