Fix publish to Artifactory crates registry (#1072)

* Remove aliases for crates rustc-std-workspace-core and rustc-std-workspace-alloc

Those aliases causes problems in Artifactory crates registry and
prevents rustix from being discovered (and as a result downloaded by cargo).
This has been introduced in version 0.38.10 when the dep: syntax for
Cargo.toml was first introduced.
My guess is that the usage of the core and alloc keywords caused issues
while uploading and indexing the crate.

* Remove rustc-std-workspace-alloc dependency

Trying to fix the breakage of the rustc-dep-of-std feature I have noticed that only the std feature uses the alloc feature.
and the alloc feature was preventing from me to just remove the dep: syntax
So I just deleted the rustc-std-alloc dep and it seems to work

* Alias alloc in lib.rs instead of Cargo.toml

The alias is only activated if the alloc feature is activated

Author: alloncm

Cargo.toml

@@ -20,8 +20,8 @@ bitflags = { version = "2.4.0", default-features = false }
 itoa = { version = "1.0.1", default-features = false, optional = true }
 
 # Special dependencies used in rustc-dep-of-std mode.
-core = { version = "1.0.0", optional = true, package = "rustc-std-workspace-core" }
-alloc = { version = "1.0.0", optional = true, package = "rustc-std-workspace-alloc" }
+core = { version = "1.0.0", optional = true, package = "rustc-std-workspace-core"}
+rustc-std-workspace-alloc = { version = "1.0.0", optional = true} # not aliased here but in lib.rs casuse of name collision with the alloc feature
 compiler_builtins = { version = '0.1.49', optional = true }
 
 # The procfs feature needs once_cell.
@@ -238,9 +238,9 @@ alloc = []
 # This is used in the port of std to rustix. This is experimental and not meant
 # for regular use.
 rustc-dep-of-std = [
-    "dep:core",
-    "dep:alloc",
-    "dep:compiler_builtins",
+    "core",
+    "rustc-std-workspace-alloc",
+    "compiler_builtins",
     "linux-raw-sys/rustc-dep-of-std",
     "bitflags/rustc-dep-of-std",
     "compiler_builtins?/rustc-dep-of-std",

src/lib.rs

@@ -127,6 +127,9 @@
     allow(unused_imports)
 )]
 
+#[cfg(all(feature = "rustc-dep-of-std", feature = "alloc"))]
+extern crate rustc_std_workspace_alloc as alloc;
+
 #[cfg(all(feature = "alloc", not(feature = "rustc-dep-of-std")))]
 extern crate alloc;