Require target=x86_64 for some packages (#41633)

This resolves issue #41148

var/spack/repos/builtin/packages/amdblis/package.py

@@ -34,6 +34,8 @@ class Amdblis(BlisBase):
 
     maintainers("amd-toolchain-support")
 
+    requires("target=x86_64:", msg="AMD blis available only on x86_64")
+
     version("4.1", sha256="a05c6c7d359232580d1d599696053ad0beeedf50f3b88d5d22ee7d34375ab577")
     version("4.0", sha256="cddd31176834a932753ac0fc4c76332868feab3e9ac607fa197d8b44c1e74a41")
     version("3.2", sha256="5a400ee4fc324e224e12f73cc37b915a00f92b400443b15ce3350278ad46fff6")

var/spack/repos/builtin/packages/amdfftw/package.py

@@ -145,6 +145,8 @@ class Amdfftw(FftwBase):
         )
         conflicts("precision=quad", msg="Quad precision is not supported with amd-app-opt")
 
+    requires("target=x86_64:", msg="AMD FFTW available only on x86_64")
+
     def configure(self, spec, prefix):
         """Configure function"""
         # Base options

var/spack/repos/builtin/packages/amdlibflame/package.py

@@ -60,6 +60,7 @@ class Amdlibflame(LibflameBase):
     conflicts("+ilp64", when="@:3.0.0", msg="ILP64 is supported from 3.0.1 onwards")
     conflicts("threads=pthreads", msg="pthread is not supported")
     conflicts("threads=openmp", when="@:3", msg="openmp is not supported by amdlibflame < 4.0")
+    requires("target=x86_64:", msg="AMD libflame available only on x86_64")
 
     patch("aocc-2.2.0.patch", when="@:2", level=1)
     patch("cray-compiler-wrapper.patch", when="@:3.0.0", level=1)

var/spack/repos/builtin/packages/amdscalapack/package.py

@@ -42,6 +42,7 @@ class Amdscalapack(ScalapackBase):
     variant("ilp64", default=False, description="Build with ILP64 support")
 
     conflicts("+ilp64", when="@:3.0", msg="ILP64 is supported from 3.1 onwards")
+    requires("target=x86_64:", msg="AMD scalapack available only on x86_64")
 
     def url_for_version(self, version):
         vers = "https://github.com/amd/{0}/archive/{1}.tar.gz"