lang/rust: Update to 1.49.0

[mikael]

Test Plan

arch	lang/rust	consumers
11.4 i386	ok	ok
11.4 amd64	ok	ok
12.2 i386	ok	ok
12.2 amd64	ok	ok
13 i386	ok	ok
13 amd64	ok	ok
powerpc64 elfv2	ok	ok
powerpc64 elfv1	ok	ok

[pkubaj]

I only tested lang/spidermonkey78 on elfv1 since this nowadays seems the most sophisticated port available for elfv1.

[pkubaj]

www/firefox builds on powerpc64 elfv2.

[pkubaj]

I did NOT test this on all powerpc* platforms where Rust works. And as it turns out, it doesn't build on powerpc64le:

error[E0432]: unresolved import `crate::spec::TargetResult`
 --> compiler/rustc_target/src/spec/powerpc64le_unknown_freebsd.rs:1:56
  |
1 | use crate::spec::{LinkerFlavor, Target, TargetOptions, TargetResult};
  |                                                        ^^^^^^^^^^^^ no `TargetResult` in `spec`

error[E0560]: struct `Target` has no field named `target_endian`
  --> compiler/rustc_target/src/spec/powerpc64le_unknown_freebsd.rs:11:9
   |
11 |         target_endian: "little".to_string(),
   |         ^^^^^^^^^^^^^ `Target` does not have this field
   |
   = note: available fields are: `llvm_target`, `pointer_width`, `arch`, `data_layout`, `options`

error[E0560]: struct `Target` has no field named `target_pointer_width`
  --> compiler/rustc_target/src/spec/powerpc64le_unknown_freebsd.rs:12:9
   |
12 |         target_pointer_width: "64".to_string(),
   |         ^^^^^^^^^^^^^^^^^^^^ `Target` does not have this field
   |
   = note: available fields are: `llvm_target`, `pointer_width`, `arch`, `data_layout`, `options`

error[E0560]: struct `Target` has no field named `target_c_int_width`
  --> compiler/rustc_target/src/spec/powerpc64le_unknown_freebsd.rs:13:9
   |
13 |         target_c_int_width: "32".to_string(),
   |         ^^^^^^^^^^^^^^^^^^ `Target` does not have this field
   |
   = note: available fields are: `llvm_target`, `pointer_width`, `arch`, `data_layout`, `options`

error[E0560]: struct `Target` has no field named `target_os`
  --> compiler/rustc_target/src/spec/powerpc64le_unknown_freebsd.rs:16:9
   |
16 |         target_os: "freebsd".to_string(),
   |         ^^^^^^^^^ `Target` does not have this field
   |
   = note: available fields are: `llvm_target`, `pointer_width`, `arch`, `data_layout`, `options`

error[E0560]: struct `Target` has no field named `target_env`
  --> compiler/rustc_target/src/spec/powerpc64le_unknown_freebsd.rs:17:9
   |
17 |         target_env: String::new(),
   |         ^^^^^^^^^^ `Target` does not have this field
   |
   = note: available fields are: `llvm_target`, `pointer_width`, `arch`, `data_layout`, `options`

error[E0560]: struct `Target` has no field named `target_vendor`
  --> compiler/rustc_target/src/spec/powerpc64le_unknown_freebsd.rs:18:9
   |
18 |         target_vendor: "unknown".to_string(),
   |         ^^^^^^^^^^^^^ `Target` does not have this field
   |
   = note: available fields are: `llvm_target`, `pointer_width`, `arch`, `data_layout`, `options`

error[E0560]: struct `Target` has no field named `linker_flavor`
  --> compiler/rustc_target/src/spec/powerpc64le_unknown_freebsd.rs:19:9
   |
19 |         linker_flavor: LinkerFlavor::Gcc,
   |         ^^^^^^^^^^^^^ `Target` does not have this field
   |
   = note: available fields are: `llvm_target`, `pointer_width`, `arch`, `data_layout`, `options`

error[E0560]: struct `TargetOptions` has no field named `target_mcount`
  --> compiler/rustc_target/src/spec/powerpc64le_unknown_freebsd.rs:20:34
   |
20 |         options: TargetOptions { target_mcount: "_mcount".to_string(), ..base },
   |                                  ^^^^^^^^^^^^^ `TargetOptions` does not have this field
   |
   = note: available fields are: `is_builtin`, `endian`, `c_int_width`, `os`, `env` ... and 87 others

error: aborting due to 9 previous errors

Some errors have detailed explanations: E0432, E0560.
For more information about an error, try `rustc --explain E0432`.

In the future, could you NOT commit the untested or only partially tested patches?