gnu: spirv-tools: Update to commit 90862fe4b1c6763b32ce683d2d32c2f281f577cf.

* gnu/packages/vulkan.scm (spirv-tools): Update to commit
90862fe4b1c6763b32ce683d2d32c2f281f577cf.

gnu/packages/vulkan.scm

@@ -74,18 +74,23 @@ and for the GLSL.std.450 extended instruction set.
                                commit "/LICENSE"))))))
 
 (define-public spirv-tools
+  ;; Keep updated in accordance with
+  ;; https://github.com/google/shaderc/blob/known-good/known_good.json
+  (let ((commit "90862fe4b1c6763b32ce683d2d32c2f281f577cf")
+        (revision "1"))
     (package
      (name "spirv-tools")
-    (version "2017.1")
+     (version (string-append "0.0-" revision "." (string-take commit 9)))
      (source
       (origin
-       (method url-fetch)
-       (uri (string-append "https://github.com/KhronosGroup/SPIRV-Tools/archive/v"
-                           version ".tar.gz"))
+       (method git-fetch)
+       (uri (git-reference
+             (url "https://github.com/KhronosGroup/SPIRV-Tools")
+             (commit commit)))
        (sha256
         (base32
-         "009vflaa71a7xhvmm23f4sdbcgdkl1k4facqkwsg6djha2sdpsqq"))
-       (file-name (string-append name "-" version ".tar.gz"))))
+         "1yq8ab6f52wcxm2azzmx70nqz8l35izd45830aikjkk1jfzmzabb"))
+       (file-name (string-append name "-" version "-checkout"))))
      (build-system cmake-build-system)
      (arguments
       `(#:configure-flags (list (string-append "-DCMAKE_INSTALL_LIBDIR="
@@ -103,7 +108,7 @@ and for the GLSL.std.450 extended instruction set.
       "The SPIR-V Tools project provides an API and commands for processing
 SPIR-V modules.  The project includes an assembler, binary module parser,
 disassembler, validator, and optimizer for SPIR-V.")
-    (license license:asl2.0)))
+     (license license:asl2.0))))
 
 (define-public glslang
   ;; Version 3.0 is too old for vulkan-icd-loader. Use a recent git commit