[CPU] Add ARM64 backend build target

Adds the new `xenia-cpu-backend-a64` build-target with linkage following the x64 backend.

premake5.lua

@@ -296,6 +296,8 @@ workspace("xenia")
 
   filter("architecture:x86_64")
     include("src/xenia/cpu/backend/x64")
+  filter("architecture:ARM64")
+    include("src/xenia/cpu/backend/a64")
   filter({})
 
   include("src/xenia/debug/ui")

src/xenia/app/premake5.lua

@@ -73,6 +73,11 @@ project("xenia-app")
       "xenia-cpu-backend-x64",
     })
 
+  filter("architecture:ARM64")
+    links({
+      "xenia-cpu-backend-a64",
+    })
+
   -- TODO(Triang3l): The emulator itself on Android.
   filter("platforms:not Android-*")
     files({

src/xenia/cpu/backend/a64/premake5.lua

@@ -0,0 +1,20 @@
+project_root = "../../../../.."
+include(project_root.."/tools/build")
+
+group("src")
+project("xenia-cpu-backend-a64")
+  uuid("495f3f3e-f5e8-489a-bd0f-289d0495bc08")
+  filter("architecture:ARM64")
+    kind("StaticLib")
+  filter("architecture:not ARM64")
+    kind("None")
+  filter({})
+  language("C++")
+  links({
+    "fmt",
+    "xenia-base",
+    "xenia-cpu",
+  })
+  defines({
+  })
+  local_platform_files()

src/xenia/cpu/ppc/testing/premake5.lua

@@ -27,6 +27,10 @@ project("xenia-cpu-ppc-tests")
     links({
       "xenia-cpu-backend-x64",
     })
+  filter("architecture:ARM64")
+    links({
+      "xenia-cpu-backend-a64",
+    })
   filter("platforms:Windows-*")
     debugdir(project_root)
     debugargs({

src/xenia/cpu/testing/premake5.lua

@@ -19,6 +19,10 @@ test_suite("xenia-cpu-tests", project_root, ".", {
       links = {
         "xenia-cpu-backend-x64",
       },
+      filter = 'architecture:ARM64',
+      links = {
+        "xenia-cpu-backend-a64",
+      },
     }
   },
 })

src/xenia/gpu/d3d12/premake5.lua

@@ -70,6 +70,11 @@ project("xenia-gpu-d3d12-trace-viewer")
       "xenia-cpu-backend-x64",
     })
 
+  filter("architecture:ARM64")
+    links({
+      "xenia-cpu-backend-a64",
+    })
+
 group("src")
 project("xenia-gpu-d3d12-trace-dump")
   uuid("686b859c-0046-44c4-a02c-41fc3fb75698")
@@ -120,3 +125,8 @@ project("xenia-gpu-d3d12-trace-dump")
     links({
       "xenia-cpu-backend-x64",
     })
+
+  filter("architecture:ARM64")
+    links({
+      "xenia-cpu-backend-a64",
+    })

src/xenia/gpu/vulkan/premake5.lua

@@ -68,6 +68,11 @@ project("xenia-gpu-vulkan-trace-viewer")
       "xenia-cpu-backend-x64",
     })
 
+  filter("architecture:ARM64")
+    links({
+      "xenia-cpu-backend-a64",
+    })
+
   filter("platforms:Linux")
     links({
       "X11",
@@ -131,6 +136,11 @@ project("xenia-gpu-vulkan-trace-dump")
       "xenia-cpu-backend-x64",
     })
 
+  filter("architecture:ARM64")
+    links({
+      "xenia-cpu-backend-a64",
+    })
+
   filter("platforms:Linux")
     links({
       "X11",