Remove unnecessary linker script preprocessing

The previous build process ran sed against the linker scripts twice:
once to replace <X> with the contents of sym_x.ld, a second time to
correct any paths referencing tools/.

The first can be replaced with INCLUDE commands, as was done in
pret/pokeemerald@7c57699 (in 2018).

The second has been unnecessary since 942c248 (also 2018).

With both of these removed there is no longer a need to have a build
step for them, and $(ELF) can take the sym_x.ld files as prerequisites
instead.

.gitignore

@@ -22,7 +22,6 @@
 *.id1
 *.id2
 *.latfont
-*.ld
 *.lz
 *.map
 *.nam

Makefile

@@ -327,19 +327,15 @@ $(OBJ_DIR)/sym_ewram.ld: sym_ewram.txt
 	$(RAMSCRGEN) ewram_data $< ENGLISH > $@
 
 ifeq ($(MODERN),0)
-LD_SCRIPT := ld_script.txt
+LD_SCRIPT := ld_script.ld
 LD_SCRIPT_DEPS := $(OBJ_DIR)/sym_bss.ld $(OBJ_DIR)/sym_common.ld $(OBJ_DIR)/sym_ewram.ld
 else
-LD_SCRIPT := ld_script_modern.txt
+LD_SCRIPT := ld_script_modern.ld
 LD_SCRIPT_DEPS :=
 endif
 
-$(OBJ_DIR)/ld_script.ld: $(LD_SCRIPT) $(LD_SCRIPT_DEPS)
+$(ELF): $(LD_SCRIPT) $(LD_SCRIPT_DEPS) $(OBJS)
-	cd $(OBJ_DIR) && sed -f ../../ld_script.sed ../../$< | sed "s#tools/#../../tools/#g" > ld_script.ld
+	@cd $(OBJ_DIR) && $(LD) $(LDFLAGS) -T ../../$< -o ../../$@ $(OBJS_REL) $(LIB)
-
-$(ELF): $(OBJ_DIR)/ld_script.ld $(OBJS)
-	@echo "cd $(OBJ_DIR) && $(LD) $(LDFLAGS) -T ld_script.ld -o ../../$@ <objects> <lib>"
-	@cd $(OBJ_DIR) && $(LD) $(LDFLAGS) -T ld_script.ld -o ../../$@ $(OBJS_REL) $(LIB)
 	$(FIX) $@ -t"$(TITLE)" -c$(GAME_CODE) -m$(MAKER_CODE) -r$(GAME_REVISION) --silent
 
 $(ROM): $(ELF)

ld_script.ld

@@ -11,7 +11,7 @@ SECTIONS {
 
         . = 0x1C000;
 
-<EWRAM>
+        INCLUDE "sym_ewram.ld"
         src/*.o(.ewram_data);
 
         *libc.a:impure.o(.data);
@@ -26,7 +26,7 @@ SECTIONS {
     ALIGN(4)
     {
         /* .bss starts at 0x3000000 */
-<BSS>
+        INCLUDE "sym_bss.ld"
         src/*.o(.bss);
         data/*.o(.bss);
 
@@ -34,7 +34,7 @@ SECTIONS {
         src/m4a.o(.bss.code);
 
         /* COMMON starts at 0x30030E0 */
-<COMMON>
+        INCLUDE "sym_common.ld"
 
         *libc.a:sbrkr.o(COMMON);
         end = .;

ld_script.sed

@@ -1,14 +0,0 @@
-/<EWRAM>/ {
-    r sym_ewram.ld
-    d
-}
-
-/<BSS>/ {
-    r sym_bss.ld
-    d
-}
-
-/<COMMON>/ {
-    r sym_common.ld
-    d
-}