Do not test aarch64 as the assembly has not been written.

Originally from Debian:

https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=975411

test cases/common/119 llvm ir and assembly/meson.build

diff --git a/test cases/common/119 llvm ir and assembly/meson.build b/test cases/common/119 llvm ir and assembly/meson.build
index fd07d87..330438b 100644
--- a/test cases/common/119 llvm ir and assembly/meson.build
+++ b/test cases/common/119 llvm ir and assembly/meson.build
@@ -1,7 +1,7 @@
 project('llvm-ir', 'c', 'cpp')
 
 cpu = host_machine.cpu_family()
-supported_cpus = ['arm', 'aarch64', 'x86', 'x86_64']
+supported_cpus = ['arm', 'x86', 'x86_64']
 
 foreach lang : ['c', 'cpp']
   cc = meson.get_compiler(lang)