fix: advance r15, even when the pipeline is reloaded from the scheduler

The PC would fall behind whenever an IRQ was called because the pipeline
was reloaded (+8 to PC), however that was never actually done by any code

Now, the PC is always incremented when the pipeline is reloaded

src/core/cpu.zig

@@ -450,8 +450,7 @@ pub const Arm7tdmi = struct {
             }
         }
 
-        if (self.pipe.flushed) self.r[15] += if (self.cpsr.t.read()) 2 else @as(u32, 4);
-        self.r[15] += if (self.cpsr.t.read()) 2 else @as(u32, 4);
+        if (!self.pipe.flushed) self.r[15] += if (self.cpsr.t.read()) 2 else @as(u32, 4);
         self.pipe.flushed = false;
     }
 
@@ -542,6 +541,8 @@ pub const Arm7tdmi = struct {
         std.debug.print("spsr: 0x{X:0>8} ", .{self.spsr.raw});
         prettyPrintPsr(&self.spsr);
 
+        std.debug.print("pipeline: {??X:0>8}\n", .{self.pipe.stage});
+
         if (self.cpsr.t.read()) {
             const opcode = self.bus.dbgRead(u16, self.r[15] - 4);
             const id = thumbIdx(opcode);
@@ -704,6 +705,8 @@ const Pipline = struct {
 
         self.stage[0] = cpu.bus.read(T, cpu.r[15]);
         self.stage[1] = cpu.bus.read(T, cpu.r[15] + if (T == u32) 4 else @as(u32, 2));
+
+        cpu.r[15] += if (T == u32) 8 else @as(u32, 4);
         self.flushed = true;
     }
 };