Fix crash upon constant dim declaration

Author: boriel

symbols/bound.py

@@ -48,13 +48,13 @@ def make_node(lower, upper, lineno):
             syntax_error(lineno, 'Array bounds must be constants')
             return None
 
-        if isinstance(lower, SymbolVAR):
+        while isinstance(lower, SymbolVAR):
             lower = lower.value
             if lower is None:  # semantic error
                 syntax_error(lineno, "Unknown lower bound for array dimension")
                 return
 
-        if isinstance(upper, SymbolVAR):
+        while isinstance(upper, SymbolVAR):
             upper = upper.value
             if upper is None:  # semantic error
                 syntax_error(lineno, "Unknown upper bound for array dimension")

tests/functional/dim_const_const.asm

@@ -0,0 +1,49 @@
+	org 32768
+__START_PROGRAM:
+	di
+	push ix
+	push iy
+	exx
+	push hl
+	exx
+	ld hl, 0
+	add hl, sp
+	ld (__CALL_BACK__), hl
+	ei
+	ld hl, 0
+	ld b, h
+	ld c, l
+__END_PROGRAM:
+	di
+	ld hl, (__CALL_BACK__)
+	ld sp, hl
+	exx
+	pop hl
+	exx
+	pop iy
+	pop ix
+	ei
+	ret
+__CALL_BACK__:
+	DEFW 0
+ZXBASIC_USER_DATA:
+_mobCoords:
+	DEFW __LABEL0
+_mobCoords.__DATA__.__PTR__:
+	DEFW _mobCoords.__DATA__
+_mobCoords.__DATA__:
+	DEFB 00h
+	DEFB 00h
+	DEFB 00h
+	DEFB 00h
+	DEFB 00h
+	DEFB 00h
+__LABEL0:
+	DEFW 0001h
+	DEFW 0002h
+	DEFB 01h
+; Defines DATA END --> HEAP size is 0
+ZXBASIC_USER_DATA_END:
+	; Defines USER DATA Length in bytes
+ZXBASIC_USER_DATA_LEN EQU ZXBASIC_USER_DATA_END - ZXBASIC_USER_DATA
+	END

tests/functional/dim_const_const.bas

@@ -0,0 +1,4 @@
+const MHEIGHT as ubyte = 2
+const MAXMOBS as ubyte = MHEIGHT
+dim mobCoords(0 to MAXMOBS, 0 to 1) as ubyte
+