Revert "gnu: Remove rust-test-generator-0.3."

This reverts commit 063f8b5e2a.

This package is needed for librsvg

gnu/packages/crates-io.scm

@@ -58900,6 +58900,33 @@ into mod, giving clear and readable test results.")
 for TLS).")
     (license (list license:expat license:asl2.0))))
 
+(define-public rust-test-generator-0.3
+  (package
+    (name "rust-test-generator")
+    (version "0.3.0")
+    (source (origin
+              (method url-fetch)
+              (uri (crate-uri "test-generator" version))
+              (file-name (string-append name "-" version ".tar.gz"))
+              (sha256
+               (base32
+                "1h03y4503jhhrks4m7xqfjya9lsx3ip5dlbldr7mgcws6j8bx5za"))))
+    (build-system cargo-build-system)
+    (arguments
+     `(#:cargo-inputs
+       (("rust-glob" ,rust-glob-0.3)
+        ("rust-proc-macro2" ,rust-proc-macro2-0.4)
+        ("rust-quote" ,rust-quote-0.6)
+        ("rust-syn" ,rust-syn-0.15))))
+    (home-page "https://github.com/frehberg/test-generator")
+    (synopsis "Generate parameterized tests from different input parameters")
+    (description
+     "This crate provides @code{#[test_resources]} and @code{#[bench_resources]}
+procedural macro attributes that generates multiple parameterized tests using
+one body with different resource input parameters.  A test is generated for
+each resource matching the specific resource location pattern.")
+    (license license:asl2.0)))
+
 (define-public rust-tester-0.9
   (package
     (name "rust-tester")