Add Debug.UNSTABLE and gate unstable target/features behind it

aeneas/src/arm64/Arm64Linux.v3

@@ -4,10 +4,10 @@
 def SPACE = AddressSpace.new("mem", false, 64, 8,
 	Alignment.new(4096), Alignment.new(8));
 def KERNEL_CALL_RETURN = Tuple.newType(Lists.cons2(Long.TYPE, Long.TYPE));
-def Arm64_LINUX_TARGET = Aeneas.registerTarget(
-		LinuxTarget.new("arm64-linux", SPACE, IntNormalizers.I64LE, Arm64Common.LOWERING,
+def X_ = if(Debug.UNSTABLE, // unstable target for now
+		Aeneas.registerTarget(LinuxTarget.new("arm64-linux", SPACE, IntNormalizers.I64LE, Arm64Common.LOWERING,
 			Arm64LinuxBackend.new(_, _, _, _, _, false), ElfConst.EM_AARCH64,
-			KERNEL_CALL_RETURN));
+			KERNEL_CALL_RETURN)));
 
 def Regs: Arm64Regs;
 def MRegs: Arm64RegSet;

aeneas/src/main/Aeneas.v3

@@ -147,6 +147,7 @@ component Aeneas {
 	def printVersion(long: bool, next: string) {
 		Terminal.put("Aeneas ");
 		Terminal.put(Version.version);
+		if (!Debug.UNSTABLE) Terminal.put(" (stable)");
 		var data = Version.buildData;
 		if (long && data != null) {
 			Terminal.put("\nBuild Data: ");

aeneas/src/main/CLOptions.v3

@@ -55,7 +55,7 @@ component CLOptions {
 		"Force inlining of direct calls to the given method(s).");
 	// Debugging options
 	def PRINT_IC		= debugOpt.newMatcherOption("print-ic",
-		"Printer internal interpreter code as it is generated.");
+		"Print internal interpreter code as it is generated.");
 	def PRINT_ID		= debugOpt.newBoolOption("print-id", false,
 		"Print additional internal IR ids.");
 	def PRINT_INLINING	= debugOpt.newBoolOption("print-inlining", false,
@@ -113,7 +113,7 @@ component CLOptions {
 	def TRACE		= runOpt.newBoolOption("trace", false,
 		"Trace execution of interpreter code.");
 	def SSA_INT		= runOpt.newBoolOption("ssa-int", true,
-		"Use the SsaInterpreter instead of the IC interpreter");
+		"Use the SsaInterpreter instead of the IC interpreter.");
 	def TRACE_PARENT	= runOpt.newBoolOption("trace-parent", false,
 		"Trace the parent of function callers during intepretation.");
 	def TRACE_CALLS		= runOpt.newMatcherOption("trace-calls",
@@ -164,7 +164,7 @@ component CLOptions {
 	def UNBOX_VARIANT_CASES	= compileOpt.newStringOption("unbox-variant-cases", null,
 		"Unbox all non-recursive variants.");
 	def REDEF_FIELD		= compileOpt.newStringOption("redef-field", null,
-		"Redefines one or more program fields, setting them to the given value.");
+		"Redefine one or more program fields, setting them to the given values.");
 	// JVM target options
 	def JVM_RT_PATH		= jvmOpt.newStringOption("jvm.rt-path", null,
 		"Specify the path to the Java runtime.");

aeneas/src/main/Debug.v3

@@ -3,4 +3,5 @@
 
 component Debug {
 	def PARANOID = false;
+	def UNSTABLE = true;
 }

aeneas/src/main/Version.v3

@@ -3,6 +3,6 @@
 
 // Updated by VCS scripts. DO NOT EDIT.
 component Version {
-	def version: string = "III-7.1758";
+	def version: string = "III-7.1759";
 	var buildData: string;
 }

aeneas/src/vst/Parser.v3

@@ -502,7 +502,7 @@ component Parser {
 			if (pt != null) rettype = ReturnType.This(Token.new(p.fileName, str, loc.0, loc.1));
 			else rettype = ReturnType.Explicit(Parser.parseTypeRef(p));
 			body = if(p.curByte == ';', EmptyStmt.new(p.token(1)), Parser.parseBlockStmt(p));
-		} else if ((start = p.optN("=>")) >= 0) {
+		} else if ((start = p.optN("=>")) >= 0) { // TODO: add option to enable simple function bodies
 			var expr = parseExpr(p);
 			rettype = ReturnType.Implicit(expr);
 			if (isDef) p.req1(';');
@@ -847,11 +847,11 @@ component Parser {
 			}
 			return parseVarExpr(p);
 		}
-		if (p.enableFunExprs && ch == 'f') {
+		if (Debug.UNSTABLE && p.enableFunExprs && ch == 'f') {
 			var start = optKeyword(p, "fun");
 			if (start != null) {
 				var id = if(Char.isIdentStart(p.curByte), parseIdentVoid(p).name);
-				var params = parseMethodParams(p);
+				var params = parseMethodParams(p); // TODO: make parameters optional
 				var t = parseReturnTypeAndBody(p, false);
 				return FunExpr.new(start, id, params, t.0, t.1);
 			}