cpu/{arm|thumb}(chore): change how branch disassembly happens

Signed-off-by: Amneesh Singh <natto@weirdnatto.in>

src/cpu/arm/disassembler.cc

@@ -1,7 +1,6 @@
 #include "cpu/arm/instruction.hh"
 #include "util/bits.hh"
 #include <format>
-#include <string>
 
 namespace matar::arm {
 std::string
@@ -13,9 +12,11 @@ Instruction::disassemble() {
         [condition](BranchAndExchange& data) {
             return std::format("BX{} R{:d}", condition, data.rn);
         },
-        [condition](Branch& data) {
-            return std::format(
-              "B{}{} 0x{:06X}", (data.link ? "L" : ""), condition, data.offset);
+            [condition](Branch& data) {
+            return std::format("B{}{} {:#06x}",
+                               (data.link ? "L" : ""),
+                               condition,
+                               static_cast<int32_t>(data.offset + 2 * INSTRUCTION_SIZE));
         },
         [condition](Multiply& data) {
             if (data.acc) {