Significantly overhaul OPT code

Simplify the mess that was option setting (2 redundant variables !?)
Move options to a separate file
Have "modules" own their options, and OPT only access them (less redundancy)
Simplify code, respect naming conventions better

include/asm/lexer.h

@@ -30,17 +30,21 @@ static inline void lexer_SetStateAtEOL(struct LexerState *state)
 	lexerStateEOL = state;
 }
 
-extern char const *binDigits;
-extern char const *gfxDigits;
+extern char binDigits[2];
+extern char gfxDigits[4];
 
-static inline void lexer_SetBinDigits(char const *digits)
+static inline void lexer_SetBinDigits(char const digits[2])
 {
-	binDigits = digits;
+	binDigits[0] = digits[0];
+	binDigits[1] = digits[1];
 }
 
-static inline void lexer_SetGfxDigits(char const *digits)
+static inline void lexer_SetGfxDigits(char const digits[4])
 {
-	gfxDigits = digits;
+	gfxDigits[0] = digits[0];
+	gfxDigits[1] = digits[1];
+	gfxDigits[2] = digits[2];
+	gfxDigits[3] = digits[3];
 }
 
 /*

include/asm/main.h

@@ -1,7 +1,7 @@
 /*
  * This file is part of RGBDS.
  *
- * Copyright (c) 1997-2018, Carsten Sorensen and RGBDS contributors.
+ * Copyright (c) 1997-2021, Carsten Sorensen and RGBDS contributors.
  *
  * SPDX-License-Identifier: MIT
  */
@@ -15,19 +15,6 @@
 
 #include "helpers.h"
 
-struct sOptions {
-	char binary[2];
-	char gbgfx[4];
-	int32_t fillchar;
-};
-
-extern char *tzNewMacro;
-extern uint32_t ulNewMacroSize;
-extern int32_t nGBGfxID;
-extern int32_t nBinaryID;
-
-extern struct sOptions DefaultOptions;
-extern struct sOptions CurrentOptions;
 extern bool haltnop;
 extern bool optimizeloads;
 extern bool verbose;
@@ -39,10 +26,6 @@ extern bool oGeneratedMissingIncludes;
 extern bool oFailedOnMissingInclude;
 extern bool oGeneratePhonyDeps;
 
-void opt_Push(void);
-void opt_Pop(void);
-void opt_Parse(char *s);
-
 /* TODO: are these really needed? */
 #define YY_FATAL_ERROR fatalerror
 

include/asm/opt.h

@@ -0,0 +1,22 @@
+/*
+ * This file is part of RGBDS.
+ *
+ * Copyright (c) 2021, Eldred Habert and RGBDS contributors.
+ *
+ * SPDX-License-Identifier: MIT
+ */
+
+#ifndef RGBDS_OPT_H
+#define RGBDS_OPT_H
+
+
+void opt_B(char chars[2]);
+void opt_G(char chars[4]);
+void opt_P(uint8_t fill);
+void opt_Parse(char const *option);
+
+void opt_Push(void);
+void opt_Pop(void);
+
+
+#endif

include/asm/section.h

@@ -14,6 +14,8 @@
 
 #include "linkdefs.h"
 
+extern uint8_t fillByte;
+
 struct Expression;
 
 struct Section {