delete aro dependency

translate-c is moving towards a package provided by the build system
(#20630).

The repository https://github.com/ziglang/translate-c/ implements C
translation using Aro. This commit deletes the Aro implementation of C
translation from the Zig repository, leaving only the Clang
implementation.

The other dependency on Aro is for the preprocessor. This must move to
`std.zig.Preprocessor`, be untangled from Aro, and independently
maintained.

There must also be added a Preprocessor Build Step, which this commit
does not do.

Furthermore, the preprocessor must be exposed as a zig compiler JIT
command rather than always being compiled into the compiler. This will
reduce binary size and time spent waiting for zig to build.

Author: andrewrk

CMakeLists.txt

@@ -532,13 +532,13 @@ set(ZIG_STAGE2_SOURCES
     src/arch/arm/Mir.zig
     src/arch/arm/abi.zig
     src/arch/arm/bits.zig
-    src/arch/riscv64/abi.zig
-    src/arch/riscv64/bits.zig
     src/arch/riscv64/CodeGen.zig
     src/arch/riscv64/Emit.zig
-    src/arch/riscv64/encoding.zig
     src/arch/riscv64/Lower.zig
     src/arch/riscv64/Mir.zig
+    src/arch/riscv64/abi.zig
+    src/arch/riscv64/bits.zig
+    src/arch/riscv64/encoding.zig
     src/arch/riscv64/mnem.zig
     src/arch/sparc64/CodeGen.zig
     src/arch/sparc64/Emit.zig
@@ -617,6 +617,7 @@ set(ZIG_STAGE2_SOURCES
     src/link/MachO/Object.zig
     src/link/MachO/Relocation.zig
     src/link/MachO/Symbol.zig
+    src/link/MachO/Thunk.zig
     src/link/MachO/UnwindInfo.zig
     src/link/MachO/ZigObject.zig
     src/link/MachO/dead_strip.zig
@@ -630,7 +631,6 @@ set(ZIG_STAGE2_SOURCES
     src/link/MachO/load_commands.zig
     src/link/MachO/relocatable.zig
     src/link/MachO/synthetic.zig
-    src/link/MachO/Thunk.zig
     src/link/MachO/uuid.zig
     src/link/NvPtx.zig
     src/link/Plan9.zig
@@ -668,6 +668,9 @@ set(ZIG_STAGE2_SOURCES
     src/target.zig
     src/tracy.zig
     src/translate_c.zig
+    src/translate_c/Tokenizer.zig
+    src/translate_c/aro.zig
+    src/translate_c/ast.zig
     src/wasi_libc.zig
 )
 
@@ -857,10 +860,8 @@ set(BUILD_ZIG2_ARGS
   -femit-bin="${ZIG2_C_SOURCE}"
   -target "${ZIG_HOST_TARGET_TRIPLE}"
   --dep "build_options"
-  --dep "aro"
   "-Mroot=src/main.zig"
   "-Mbuild_options=${ZIG_CONFIG_ZIG_OUT}"
-  "-Maro=lib/compiler/aro/aro.zig"
 )
 
 add_custom_command(

build.zig

@@ -668,18 +668,6 @@ fn addCompilerStep(b: *std.Build, options: AddCompilerStepOptions) *std.Build.St
         .valgrind = options.valgrind,
     });
 
-    const aro_mod = b.createModule(.{
-        .root_source_file = b.path("lib/compiler/aro/aro.zig"),
-    });
-
-    const aro_translate_c_mod = b.createModule(.{
-        .root_source_file = b.path("lib/compiler/aro_translate_c.zig"),
-    });
-
-    aro_translate_c_mod.addImport("aro", aro_mod);
-    compiler_mod.addImport("aro", aro_mod);
-    compiler_mod.addImport("aro_translate_c", aro_translate_c_mod);
-
     const exe = b.addExecutable(.{
         .name = "zig",
         .max_rss = 7_800_000_000,