Refactor builds to use target profiles and discovery; remove architecture checker

toolchain/targets/x86_64.sh

@@ -0,0 +1,28 @@
+#!/usr/bin/env bash
+# Copyright 2026 Aaron Hance
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+# http://www.apache.org/licenses/LICENSE-2.0
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+PASCAL_COMPILER=ppcx64
+PASCAL_ENTRY="$ARCH_SOURCE_ROOT/arch.$ASURO_ARCH.boot.pas"
+PASCAL_OPTIONS=(-O2)
+C_TARGET_OPTIONS=(-m64)
+NASM_FORMAT=elf64
+LD_FORMAT=elf_x86_64
+LINKER_SCRIPT="$TARGET_TOOLCHAIN_DIR/linker.script"
+# The bootstrap does not depend on the desktop or hosted runtime.
+BUILD_STEPS=(stub sources link isogen)
+case "${ASURO_BOOT_TEST:-none}" in
+    none) ;;
+    ud|pf|df) PASCAL_OPTIONS+=("-dASURO_TEST_${ASURO_BOOT_TEST^^}") ;;
+    *) echo "Unknown ASURO_BOOT_TEST" >&2; exit 1 ;;
+esac
+
+KERNEL_VALIDATOR=(grub-file --is-x86-multiboot)