Make sure we add configured lib paths to the Makefile generated by mkmkf

This enables using custom directories that are not standard system
directories where libraries are located. On MRI this is handled by
passing down CONFIGURE_ARGS, but we prefer explicitly configuring this
so we are not bound in our configure options by those used in MRI
extensions.

lib/18/mkmf.rb

@@ -1720,6 +1720,16 @@ def init_mkmf(config = CONFIG)
   $LIBRUBYARG_SHARED = config['LIBRUBYARG_SHARED']
   $DEFLIBPATH = [$extmk ? "$(topdir)" : "$(libdir)"]
   $DEFLIBPATH.unshift(".")
+
+  # ---------------------- Changed for Rubinius --------------------------------
+  # Make sure that we include the lib paths here that we may find libraries so
+  # that built in extensions will also find them if they have been configured
+  # at build time for Rubinius.
+  Rubinius::BUILD_CONFIG[:lib_dirs].each do |lib|
+    $DEFLIBPATH << lib
+  end
+  # ----------------------------------------------------------------------------
+
   $LIBPATH = []
   $INSTALLFILES = []
   $NONINSTALLFILES = [/~\z/, /\A#.*#\z/, /\A\.#/, /\.bak\z/i, /\.orig\z/, /\.rej\z/, /\.l[ao]\z/, /\.o\z/]

lib/19/mkmf.rb

@@ -2166,6 +2166,16 @@ def init_mkmf(config = CONFIG, rbconfig = RbConfig::CONFIG)
   $LIBRUBYARG_SHARED = config['LIBRUBYARG_SHARED']
   $DEFLIBPATH = [$extmk ? "$(topdir)" : "$(libdir)"]
   $DEFLIBPATH.unshift(".")
+
+  # ---------------------- Changed for Rubinius --------------------------------
+  # Make sure that we include the lib paths here that we may find libraries so
+  # that built in extensions will also find them if they have been configured
+  # at build time for Rubinius.
+  Rubinius::BUILD_CONFIG[:lib_dirs].each do |lib|
+    $DEFLIBPATH << lib
+  end
+  # ----------------------------------------------------------------------------
+
   $LIBPATH = []
   $INSTALLFILES = []
   $NONINSTALLFILES = [/~\z/, /\A#.*#\z/, /\A\.#/, /\.bak\z/i, /\.orig\z/, /\.rej\z/, /\.l[ao]\z/, /\.o\z/]