Remove obsolete -Z debug-info rustc flag.

Upstream, it's been changed to ``--debuginfo`` (short form ``-g``), but
we're not really doing anything that requires the debug info at present
(earlier on it was a more common need!), so we may as well remove it.

Author: chris-morgan

Makefile

@@ -1,7 +1,7 @@
 RUSTC ?= rustc
 RUSTDOC ?= rustdoc
 RUSTPKG ?= rustpkg
-RUSTFLAGS ?= -O -Z debug-info
+RUSTFLAGS ?= -O
 RUST_REPOSITORY ?= ../rust
 RUST_CTAGS ?= $(RUST_REPOSITORY)/src/etc/ctags.rust
 VERSION=0.1-pre