Consistently use UINT32_MAX, not -1, for uint32_t values

src/asm/fstack.cpp

@@ -162,7 +162,7 @@ bool yywrap() {
 		// If the node is referenced outside this context, we can't edit it, so duplicate it
 		if (context.fileInfo.use_count() > 1) {
 			context.fileInfo = std::make_shared<FileStackNode>(*context.fileInfo);
-			context.fileInfo->ID = -1; // The copy is not yet registered
+			context.fileInfo->ID = UINT32_MAX; // The copy is not yet registered
 		}
 
 		std::vector<uint32_t> &fileInfoIters = context.fileInfo->iters();

src/asm/parser.y

@@ -1702,7 +1702,7 @@ sect_org:
 	}
 	| LBRACK uconst RBRACK {
 		$$ = $2;
-		if ($$ < 0 || $$ >= 0x10000) {
+		if ($$ < 0 || $$ > 0xFFFF) {
 			::error("Address $%x is not 16-bit\n", $$);
 			$$ = -1;
 		}

src/asm/symbol.cpp

@@ -169,7 +169,7 @@ static Symbol &createSymbol(std::string const &symName) {
 	sym.section = nullptr;
 	sym.src = fstk_GetFileStack();
 	sym.fileLine = sym.src ? lexer_GetLineNo() : 0;
-	sym.ID = -1;
+	sym.ID = UINT32_MAX;
 	sym.defIndex = nextDefIndex++;
 
 	return sym;