Use labels instead of constants for HRAM

Use explicit ldh instruction to access HRAM locations, don't rely on optimizing ld

engine/overworld/init_map.asm

@@ -1,31 +1,31 @@
 ReanchorBGMap_NoOAMUpdate::
 	call DelayFrame
-	ld a, [hOAMUpdate]
+	ldh a, [hOAMUpdate]
 	push af
 
 	ld a, $1
-	ld [hOAMUpdate], a
-	ld a, [hBGMapMode]
+	ldh [hOAMUpdate], a
+	ldh a, [hBGMapMode]
 	push af
 	xor a
-	ld [hBGMapMode], a
+	ldh [hBGMapMode], a
 
 	call .ReanchorBGMap
 
 	pop af
-	ld [hBGMapMode], a
+	ldh [hBGMapMode], a
 	pop af
-	ld [hOAMUpdate], a
+	ldh [hOAMUpdate], a
 	ld hl, wVramState
 	set 6, [hl]
 	ret
 
 .ReanchorBGMap:
 	xor a
-	ld [hLCDCPointer], a
-	ld [hBGMapMode], a
+	ldh [hLCDCPointer], a
+	ldh [hBGMapMode], a
 	ld a, $90
-	ld [hWY], a
+	ldh [hWY], a
 	call OverworldTextModeSwitch
 	ld a, HIGH(vBGMap1)
 	call .LoadBGMapAddrIntoHRAM
@@ -33,10 +33,10 @@ ReanchorBGMap_NoOAMUpdate::
 	farcall LoadOW_BGPal7
 	farcall ApplyPals
 	ld a, $1
-	ld [hCGBPalUpdate], a
+	ldh [hCGBPalUpdate], a
 	xor a
-	ld [hBGMapMode], a
-	ld [hWY], a
+	ldh [hBGMapMode], a
+	ldh [hWY], a
 	farcall HDMATransfer_FillBGMap0WithBlack ; no need to farcall
 	ld a, HIGH(vBGMap0)
 	call .LoadBGMapAddrIntoHRAM
@@ -45,59 +45,59 @@ ReanchorBGMap_NoOAMUpdate::
 	ld a, HIGH(vBGMap0)
 	ld [wBGMapAnchor + 1], a
 	xor a
-	ld [hSCX], a
-	ld [hSCY], a
+	ldh [hSCX], a
+	ldh [hSCY], a
 	call ApplyBGMapAnchorToObjects
 	ret
 
 .LoadBGMapAddrIntoHRAM:
-	ld [hBGMapAddress + 1], a
+	ldh [hBGMapAddress + 1], a
 	xor a
-	ld [hBGMapAddress], a
+	ldh [hBGMapAddress], a
 	ret
 
 LoadFonts_NoOAMUpdate::
-	ld a, [hOAMUpdate]
+	ldh a, [hOAMUpdate]
 	push af
 	ld a, $1
-	ld [hOAMUpdate], a
+	ldh [hOAMUpdate], a
 
 	call .LoadGFX
 
 	pop af
-	ld [hOAMUpdate], a
+	ldh [hOAMUpdate], a
 	ret
 
 .LoadGFX:
 	call LoadFontsExtra
 	ld a, $90
-	ld [hWY], a
+	ldh [hWY], a
 	call SafeUpdateSprites
 	call LoadStandardFont
 	ret
 
 HDMATransfer_FillBGMap0WithBlack:
-	ld a, [rSVBK]
+	ldh a, [rSVBK]
 	push af
 	ld a, BANK(wDecompressScratch)
-	ld [rSVBK], a
+	ldh [rSVBK], a
 
 	ld a, "■"
 	ld hl, wDecompressScratch
 	ld bc, wScratchAttrMap - wDecompressScratch
 	call ByteFill
 	ld a, HIGH(wDecompressScratch)
-	ld [rHDMA1], a
+	ldh [rHDMA1], a
 	ld a, LOW(wDecompressScratch)
-	ld [rHDMA2], a
+	ldh [rHDMA2], a
 	ld a, HIGH(vBGMap0 % $8000)
-	ld [rHDMA3], a
+	ldh [rHDMA3], a
 	ld a, LOW(vBGMap0 % $8000)
-	ld [rHDMA4], a
+	ldh [rHDMA4], a
 	ld a, $3f
-	ld [hDMATransfer], a
+	ldh [hDMATransfer], a
 	call DelayFrame
 
 	pop af
-	ld [rSVBK], a
+	ldh [rSVBK], a
 	ret