Initial AArch32 structure

Add a simple AArch32 assembler:
- does its own memory management using new/delete (just for testing)
- implement a single `add` function
- test to see if encoded instruction is correct

PiperOrigin-RevId: 414463789
diff --git a/BUILD.bazel b/BUILD.bazel
index 6b8244b..9f536ea 100644
--- a/BUILD.bazel
+++ b/BUILD.bazel
@@ -7980,6 +7980,14 @@
 )
 
 xnnpack_cc_library(
+    name = "aarch32_assembler",
+    srcs = [
+        "src/jit/aarch32-assembler.cc",
+    ],
+    hdrs = INTERNAL_HDRS + ["src/xnnpack/aarch32-assembler.h"],
+)
+
+xnnpack_cc_library(
     name = "XNNPACK",
     srcs = [
         "src/init.c",
@@ -11183,6 +11191,16 @@
     ],
 )
 
+xnnpack_unit_test(
+    name = "aarch32_assembler_test",
+    srcs = [
+        "test/aarch32-assembler.cc",
+    ],
+    deps = [
+        ":aarch32_assembler",
+    ],
+)
+
 ############################# Build configurations #############################
 
 # Enables usage of assembly kernels.