gnu: Add MLIR 15.

* gnu/packages/llvm.scm (mlir-15): New variable.

Change-Id: Idf0d2e406b7705a8d7de0dbda66d358c64c00d66
Signed-off-by: Ludovic Courtès <ludo@gnu.org>
Modified-by: Ludovic Courtès <ludo@gnu.org>

gnu/packages/llvm.scm

@@ -1616,14 +1616,16 @@ requirements according to version 1.1 of the OpenCL specification.")
     ;; Apache license 2.0 with LLVM exception
     (license license:asl2.0)))
 
-(define-public mlir-19
+(define (mlir-from-llvm llvm)
+  "Produce MLIR with dependencies on LLVM."
   (package
     (name "mlir")
-    (version (package-version llvm-19))
+    (version (package-version llvm))
     (source (llvm-monorepo version))
     (build-system cmake-build-system)
+    (native-inputs (package-native-inputs llvm))
     (inputs
-     (list llvm-19))
+     (list llvm))
     (arguments
      (list #:build-type "Release"
            #:configure-flags
@@ -1644,6 +1646,12 @@ reduce the cost of building domain specific compilers, and aid in connecting
 existing compilers together.")
     (license license:asl2.0))) ; With LLVM exception
 
+(define-public mlir-19
+  (mlir-from-llvm llvm-19))
+
+(define-public mlir-15
+  (mlir-from-llvm llvm-15))
+
 (define-public python-llvmlite
   (package
     (name "python-llvmlite")