build: introduce bazel support for Darwin ARM64 builds

This was recently added to the CMake build system but was not replicated
to the bazel build. Attempt to bring this into parity. While the Darwin
ARM64 port is incomplete, this allows us to maintain build system
parity.

Author: compnerd

BUILD

@@ -37,6 +37,14 @@ config_setting(
     ],
 )
 
+config_setting(
+    name = "darwin-arm64",
+    constraint_values = [
+        "@platforms//os:macos",
+        "@platforms//cpu:arm64",
+    ]
+)
+
 config_setting(
     name = "darwin-x86_64",
     constraint_values = [
@@ -464,6 +472,12 @@ filegroup(
             "Sources/Host/Linux/X86_64/PTraceX86_64.cpp",
             "Sources/Target/Linux/X86_64/ProcessX86_64.cpp",
         ],
+        ":darwin-arm64": [
+            "Sources/Host/Darwin/ARM64/MachARM64.cpp",
+            "Sources/Host/Darwin/ARM64/PTraceARM64.cpp",
+            "Sources/Target/Darwin/ARM64/ProcessARM64.cpp",
+            "Sources/Target/Darwin/ARM64/ThreadARM64.cpp",
+        ],
         ":darwin-x86_64": [
             "Sources/Host/Darwin/X86_64/MachX86_64.cpp",
             "Sources/Host/Darwin/X86_64/PTraceX86_64.cpp",