cargo: Use the library name instead of package name

The library name defaults to its package name, but it can be different.
For example:
- package name: cairo-sys-rs
- library name: cairo-sys
- dependency name: ffi

mesonbuild/cargo/interpreter.py

@@ -648,7 +648,9 @@ class Interpreter:
             dep = pkg.manifest.dependencies[name]
             dependencies.append(build.identifier(_dependency_varname(dep.package)))
             if name != dep.package:
-                dependency_map[build.string(fixup_meson_varname(dep.package))] = build.string(name)
+                dep_pkg = self._dep_package(dep)
+                dep_lib_name = dep_pkg.manifest.lib.name
+                dependency_map[build.string(fixup_meson_varname(dep_lib_name))] = build.string(name)
 
         rust_args: T.List[mparser.BaseNode] = [
             build.identifier('features_args'),
@@ -658,7 +660,7 @@ class Interpreter:
         dependencies.append(build.identifier(_extra_deps_varname()))
 
         posargs: T.List[mparser.BaseNode] = [
-            build.string(fixup_meson_varname(pkg.manifest.package.name)),
+            build.string(fixup_meson_varname(pkg.manifest.lib.name)),
             build.string(pkg.manifest.lib.path),
         ]
 

test cases/rust/22 cargo subproject/subprojects/foo-0-rs/Cargo.toml

@@ -24,6 +24,9 @@ mybar = { version = "0.1", package = "bar", default-features = false }
 version = "0.0.1"
 features = ["f1"]
 
+[dependencies.libname]
+version = "1"
+
 [features]
 default = ["f1"]
 f1 = ["f2", "f3"]

test cases/rust/22 cargo subproject/subprojects/foo-0-rs/lib.rs

@@ -1,4 +1,5 @@
 extern crate common;
+extern crate libothername;
 
 extern "C" {
     fn extra_func() -> i32;
@@ -8,6 +9,7 @@ extern "C" {
 #[no_mangle]
 pub extern "C" fn rust_func() -> i32 {
     assert!(common::common_func() == 0);
+    assert!(libothername::stuff() == 42);
     let v: i32;
     unsafe {
          v = extra_func();

test cases/rust/22 cargo subproject/subprojects/libname-1-rs.wrap

@@ -0,0 +1,2 @@
+[wrap-file]
+method = cargo

test cases/rust/22 cargo subproject/subprojects/libname-1-rs/Cargo.toml

@@ -0,0 +1,7 @@
+[package]
+name = "libname"
+version = "1"
+
+[lib]
+name="libothername"
+path = "lib.rs"

test cases/rust/22 cargo subproject/subprojects/libname-1-rs/lib.rs

@@ -0,0 +1,3 @@
+pub fn stuff() -> i32 {
+    42
+}