Move _heap.h to the compiler include dir.

Create heap.inc and use that from the assembler code.
Rename heap related _h... variables to _heap...
Add _heapmaxavail and _heapmemavail functions.


git-svn-id: svn://svn.cc65.org/cc65/trunk@1912 b7a2c559-68d2-44c3-8de9-860c34a00d81

asminc/_heap.inc

@@ -0,0 +1,25 @@
+;
+; _heap.inc
+;
+; (C) Copyright 2003 Ullrich von Bassewitz (uz@cc65.org)
+;
+
+; Assembler include file that makes the constants and structures in _heap.h
+; available for asm code.
+
+HEAP_ADMIN_SPACE        =       2
+HEAP_MIN_BLOCKSIZE      =       6       ; Minimum size of an allocated block
+
+; Struct freeblock offsets and size. NOTE: For performance reasons, the asm
+; code often uses increment/decrement operators to access other offsets, so
+; just changing offsets here will probably not work.
+freeblock_size  = 0
+freeblock_next  = 2
+freeblock_prev  = 4
+
+; Variables
+.global         __heaporg
+.global         __heapptr
+.global         __heapend
+.global         __heapfirst
+.global         __heaplast