all: add LLVM 22 support

Builder:
- Update clang.cpp for LLVM 22 API changes: DiagnosticOptions is no
  longer ref-counted, TextDiagnosticPrinter and DiagnosticsEngine take
  references instead of pointers, createDiagnostics() signature changed.
- Update cc1as.cpp: clang/Driver/Options.h moved to
  clang/Options/Options.h, namespace changed from clang::driver::options
  to clang::options, MCInstPrinter now passed as unique_ptr.
- Add new LLVM 22 libraries to GNUmakefile: clangAnalysisLifetimeSafety,
  clangOptions, LLVMDTLTO, and dtlto component.
- Add llvm22 build tag to all build/test commands.

CGo:
- Handle CXType_Unexposed in libclang.go by resolving via canonical
  type. LLVM 22 reports builtin type aliases (e.g. __size_t) as
  Unexposed instead of Typedef.
- Always make C typedefs into Go type aliases. LLVM 22 changed
  getTypedefDeclUnderlyingType to return CXType_Enum directly instead
  of wrapping in an elaborated type.

Compileopts:
- Add build-tag-guarded ClangTriple() to substitute wasm32-unknown-wasi
  with wasm32-unknown-wasip1 for LLVM 22 (deprecated triple).
- Add build-tag-guarded patchFeatures() to map renamed Xtensa features
  (atomctl, memctl, timerint, esp32s3) for LLVM 22.

Targets:
- Remove -zca from RISC-V target feature strings (esp32c3, esp32c6,
  fe310, k210, riscv-qemu, tkey). LLVM 22 now implies +zca from +c.
- Remove -zcd from k210. LLVM 22 now implies +zcd from +c,+d.

Tests:
- Change TestClangAttributes to check individual feature flags instead
  of exact string match, allowing new LLVM features without failures.
- Update TestBinarySize expected values for LLVM 22 codegen.

Signed-off-by: deadprogram <ron@hybridgroup.com>

cgo/libclang.go

@@ -330,10 +330,8 @@ func (f *cgoFile) createASTNode(name string, c clangCursor) (ast.Node, any) {
 				NamePos: pos,
 				Name:    typeName,
 			},
-			Type: f.makeASTType(underlyingType, pos),
-		}
-		if underlyingType.kind != C.CXType_Enum {
-			typeSpec.Assign = pos
+			Assign: pos,
+			Type:   f.makeASTType(underlyingType, pos),
 		}
 		return typeSpec, nil
 	case C.CXCursor_VarDecl:
@@ -806,6 +804,14 @@ func (f *cgoFile) makeASTType(typ C.CXType, pos token.Pos) ast.Expr {
 			f.addError(pos, fmt.Sprintf("unknown elaborated type (libclang type kind %s)", typeKindSpelling))
 			typeName = "<unknown>"
 		}
+	case C.CXType_Unexposed:
+		// LLVM 22+ may report certain builtin type aliases (e.g. __size_t)
+		// as Unexposed. Resolve via the canonical type.
+		canonical := C.clang_getCanonicalType(typ)
+		if canonical.kind != C.CXType_Unexposed && canonical.kind != C.CXType_Invalid {
+			return f.makeASTType(canonical, pos)
+		}
+		// If still unexposed, fall through to the error below.
 	case C.CXType_Record:
 		cursor := C.tinygo_clang_getTypeDeclaration(typ)
 		name := getString(C.tinygo_clang_getCursorSpelling(cursor))