Encode codemap and span information in crate metadata.

This allows to create proper debuginfo line information for items inlined from other crates (e.g. instantiations of generics).
Only the codemap's 'metadata' is stored in a crate's metadata. That is, just filename, line-beginnings, etc. but not the actual source code itself. We are thus missing the opportunity of making Rust the first "open-source-only" programming language out there. Pity.

src/test/auxiliary/cross_crate_spans.rs

@@ -0,0 +1,26 @@
+// Copyright 2013-2015 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+#![crate_type = "rlib"]
+#![omit_gdb_pretty_printer_section]
+
+// no-prefer-dynamic
+// compile-flags:-g
+
+pub fn generic_function<T: Clone>(val: T) -> (T, T) {
+    let result = (val.clone(), val.clone());
+    let a_variable: u32 = 123456789;
+    let another_variable: f64 = 123456789.5;
+    zzz();
+    result
+}
+
+#[inline(never)]
+fn zzz() {()}

src/test/debuginfo/cross-crate-spans.rs

@@ -0,0 +1,74 @@
+// Copyright 2013-2015 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+#![omit_gdb_pretty_printer_section]
+
+// ignore-android: FIXME(#10381)
+// min-lldb-version: 310
+
+// aux-build:cross_crate_spans.rs
+extern crate cross_crate_spans;
+
+// compile-flags:-g
+
+
+// === GDB TESTS ===================================================================================
+
+// gdb-command:break cross_crate_spans.rs:21
+// gdb-command:run
+
+// gdb-command:print result
+// gdb-check:$1 = {17, 17}
+// gdb-command:print a_variable
+// gdb-check:$2 = 123456789
+// gdb-command:print another_variable
+// gdb-check:$3 = 123456789.5
+// gdb-command:continue
+
+// gdb-command:print result
+// gdb-check:$4 = {1212, 1212}
+// gdb-command:print a_variable
+// gdb-check:$5 = 123456789
+// gdb-command:print another_variable
+// gdb-check:$6 = 123456789.5
+// gdb-command:continue
+
+
+
+// === LLDB TESTS ==================================================================================
+
+// lldb-command:b cross_crate_spans.rs:21
+// lldb-command:run
+
+// lldb-command:print result
+// lldb-check:[...]$0 = (17, 17)
+// lldb-command:print a_variable
+// lldb-check:[...]$1 = 123456789
+// lldb-command:print another_variable
+// lldb-check:[...]$2 = 123456789.5
+// lldb-command:continue
+
+// lldb-command:print result
+// lldb-check:[...]$3 = (1212, 1212)
+// lldb-command:print a_variable
+// lldb-check:[...]$4 = 123456789
+// lldb-command:print another_variable
+// lldb-check:[...]$5 = 123456789.5
+// lldb-command:continue
+
+
+// This test makes sure that we can break in functions inlined from other crates.
+
+fn main() {
+
+    let _ = cross_crate_spans::generic_function(17u32);
+    let _ = cross_crate_spans::generic_function(1212i16);
+
+}