linker: arc: add ARC-specific debug sections

ARC architecture has some additional .arcextmap debug sections used by
debuggers to understand extension-specific instructions. These sections
could safely be ignored, but doing this causes warnings at least with
ARC MWDT toolchain.

Signed-off-by: Ilya Tagunov <[email protected]>

Author: tagunil

include/zephyr/arch/arc/v2/linker.ld

@@ -291,10 +291,16 @@ SECTIONS {
 
 #include <zephyr/linker/ram-end.ld>
 
-    GROUP_END(RAMABLE_REGION)
+	GROUP_END(RAMABLE_REGION)
 
 #include <zephyr/linker/debug-sections.ld>
 
+	SECTION_PROLOGUE(.arcextmap, 0,) {
+		*(.arcextmap)
+		*(.arcextmap.*)
+		*(.gnu.linkonce.arcextmap.*)
+	}
+
 	SECTION_PROLOGUE(.ARC.attributes, 0,) {
 		KEEP(*(.ARC.attributes))
 		KEEP(*(.gnu.attributes))