std.builtin: Remove CallingConvention.arm_(apcs,aapcs16_vfp).

* arm_apcs is the long dead "OABI" which we never had working support for.
* arm_aapcs16_vfp is for arm-watchos-none which is a dead target that we've
  dropped support for.

lib/std/Target.zig

@@ -1753,10 +1753,8 @@ pub const Cpu = struct {
                 .aarch64_vfabi_sve,
                 => &.{ .aarch64, .aarch64_be },
 
-                .arm_apcs,
                 .arm_aapcs,
                 .arm_aapcs_vfp,
-                .arm_aapcs16_vfp,
                 .arm_interrupt,
                 => &.{ .arm, .armeb, .thumb, .thumbeb },
 

lib/std/builtin.zig

@@ -220,8 +220,6 @@ pub const CallingConvention = union(enum(u8)) {
     };
     /// Deprecated; use `.x86_thiscall`.
     pub const Thiscall: CallingConvention = .{ .x86_thiscall = .{} };
-    /// Deprecated; do not use.
-    pub const APCS: CallingConvention = .{ .arm_apcs = .{} };
     /// Deprecated; use `.arm_aapcs`.
     pub const AAPCS: CallingConvention = .{ .arm_aapcs = .{} };
     /// Deprecated; use `.arm_aapcs_vfp`.
@@ -284,14 +282,10 @@ pub const CallingConvention = union(enum(u8)) {
     aarch64_vfabi_sve: CommonOptions,
 
     // Calling convetions for the `arm`, `armeb`, `thumb`, and `thumbeb` architectures.
-    /// Deprecated; do not use.
-    arm_apcs: CommonOptions, // Removal of `arm_apcs` is blocked by #21842.
     /// ARM Architecture Procedure Call Standard
     arm_aapcs: CommonOptions,
     /// ARM Architecture Procedure Call Standard Vector Floating-Point
     arm_aapcs_vfp: CommonOptions,
-    /// Deprecated; do not use.
-    arm_aapcs16_vfp: CommonOptions, // Removal of `arm_aapcs16_vfp` is blocked by #21842.
     arm_interrupt: ArmInterruptOptions,
 
     // Calling conventions for the `mips64` and `mips64el` architectures.

src/Sema.zig

@@ -9407,10 +9407,8 @@ const calling_conventions_supporting_var_args = [_]std.builtin.CallingConvention
     .aarch64_aapcs_win,
     .aarch64_vfabi,
     .aarch64_vfabi_sve,
-    .arm_apcs,
     .arm_aapcs,
     .arm_aapcs_vfp,
-    .arm_aapcs16_vfp,
     .mips64_n64,
     .mips64_n32,
     .mips_o32,

src/Zcu.zig

@@ -4209,9 +4209,7 @@ pub fn callconvSupported(zcu: *Zcu, cc: std.builtin.CallingConvention) union(enu
                 => |opts| opts.incoming_stack_alignment == null,
 
                 .arm_aapcs_vfp,
-                => |opts| opts.incoming_stack_alignment == null and target.os.tag != .watchos,
+                => |opts| opts.incoming_stack_alignment == null,
-                .arm_aapcs16_vfp,
-                => |opts| opts.incoming_stack_alignment == null and target.os.tag == .watchos,
 
                 .arm_interrupt,
                 => |opts| opts.incoming_stack_alignment == null,

src/codegen/c.zig

@@ -7725,7 +7725,7 @@ fn toCallingConvention(cc: std.builtin.CallingConvention, zcu: *Zcu) ?[]const u8
         .aarch64_vfabi_sve => "aarch64_sve_pcs",
 
         .arm_aapcs => "pcs(\"aapcs\")",
-        .arm_aapcs_vfp, .arm_aapcs16_vfp => "pcs(\"aapcs-vfp\")",
+        .arm_aapcs_vfp => "pcs(\"aapcs-vfp\")",
 
         .arm_interrupt => |opts| switch (opts.type) {
             .generic => "interrupt",

src/codegen/llvm.zig

@@ -11766,16 +11766,8 @@ fn toLlvmCallConvTag(cc_tag: std.builtin.CallingConvention.Tag, target: std.Targ
         .x86_interrupt => .x86_intrcc,
         .aarch64_vfabi => .aarch64_vector_pcs,
         .aarch64_vfabi_sve => .aarch64_sve_vector_pcs,
-        .arm_apcs => .arm_apcscc,
         .arm_aapcs => .arm_aapcscc,
-        .arm_aapcs_vfp => if (target.os.tag != .watchos)
+        .arm_aapcs_vfp => .arm_aapcs_vfpcc,
-            .arm_aapcs_vfpcc
-        else
-            null,
-        .arm_aapcs16_vfp => if (target.os.tag == .watchos)
-            .arm_aapcs_vfpcc
-        else
-            null,
         .riscv64_lp64_v => .riscv_vectorcallcc,
         .riscv32_ilp32_v => .riscv_vectorcallcc,
         .avr_builtin => .avr_builtincc,
@@ -12001,7 +11993,7 @@ fn firstParamSRet(fn_info: InternPool.Key.FuncType, zcu: *Zcu, target: std.Targe
         .aarch64_aapcs_darwin,
         .aarch64_aapcs_win,
         => aarch64_c_abi.classifyType(return_type, zcu) == .memory,
-        .arm_aapcs, .arm_aapcs_vfp, .arm_aapcs16_vfp => switch (arm_c_abi.classifyType(return_type, zcu, .ret)) {
+        .arm_aapcs, .arm_aapcs_vfp => switch (arm_c_abi.classifyType(return_type, zcu, .ret)) {
             .memory, .i64_array => true,
             .i32_array => |size| size != 1,
             .byval => false,
@@ -12051,7 +12043,7 @@ fn lowerFnRetTy(o: *Object, fn_info: InternPool.Key.FuncType) Allocator.Error!Bu
             .integer => return o.builder.intType(@intCast(return_type.bitSize(zcu))),
             .double_integer => return o.builder.arrayType(2, .i64),
         },
-        .arm_aapcs, .arm_aapcs_vfp, .arm_aapcs16_vfp => switch (arm_c_abi.classifyType(return_type, zcu, .ret)) {
+        .arm_aapcs, .arm_aapcs_vfp => switch (arm_c_abi.classifyType(return_type, zcu, .ret)) {
             .memory, .i64_array => return .void,
             .i32_array => |len| return if (len == 1) .i32 else .void,
             .byval => return o.lowerType(return_type),
@@ -12300,7 +12292,7 @@ const ParamTypeIterator = struct {
                     .double_integer => return Lowering{ .i64_array = 2 },
                 }
             },
-            .arm_aapcs, .arm_aapcs_vfp, .arm_aapcs16_vfp => {
+            .arm_aapcs, .arm_aapcs_vfp => {
                 it.zig_index += 1;
                 it.llvm_index += 1;
                 switch (arm_c_abi.classifyType(ty, zcu, .arg)) {

src/link/Dwarf.zig

@@ -3538,11 +3538,8 @@ fn updateLazyType(
                     .aarch64_vfabi => .LLVM_AAPCS,
                     .aarch64_vfabi_sve => .LLVM_AAPCS,
 
-                    .arm_apcs => .normal,
                     .arm_aapcs => .LLVM_AAPCS,
-                    .arm_aapcs_vfp,
+                    .arm_aapcs_vfp => .LLVM_AAPCS_VFP,
-                    .arm_aapcs16_vfp,
-                    => .LLVM_AAPCS_VFP,
 
                     .riscv64_lp64_v,
                     .riscv32_ilp32_v,

test/cases/compile_errors/callconv_apcs_aapcs_aapcsvfp_on_unsupported_platform.zig

@@ -1,10 +1,8 @@
-export fn entry1() callconv(.APCS) void {}
 export fn entry2() callconv(.AAPCS) void {}
 export fn entry3() callconv(.AAPCSVFP) void {}
 
 // error
 // target=x86_64-linux-none
 //
-// :1:30: error: calling convention 'arm_apcs' only available on architectures 'arm', 'armeb', 'thumb', 'thumbeb'
+// :1:30: error: calling convention 'arm_aapcs' only available on architectures 'arm', 'armeb', 'thumb', 'thumbeb'
-// :2:30: error: calling convention 'arm_aapcs' only available on architectures 'arm', 'armeb', 'thumb', 'thumbeb'
+// :2:30: error: calling convention 'arm_aapcs_vfp' only available on architectures 'arm', 'armeb', 'thumb', 'thumbeb'
-// :3:30: error: calling convention 'arm_aapcs_vfp' only available on architectures 'arm', 'armeb', 'thumb', 'thumbeb'