core_timing: Convert core timing into a class

Gets rid of the largest set of mutable global state within the core.
This also paves a way for eliminating usages of GetInstance() on the
System class as a follow-up.

Note that no behavioral changes have been made, and this simply extracts
the functionality into a class. This also has the benefit of making
dependencies on the core timing functionality explicit within the
relevant interfaces.

src/core/arm/dynarmic/arm_dynarmic.cpp

@@ -112,14 +112,14 @@ public:
         // Always execute at least one tick.
         amortized_ticks = std::max<u64>(amortized_ticks, 1);
 
-        Timing::AddTicks(amortized_ticks);
+        parent.core_timing.AddTicks(amortized_ticks);
         num_interpreted_instructions = 0;
     }
     u64 GetTicksRemaining() override {
-        return std::max(Timing::GetDowncount(), 0);
+        return std::max(parent.core_timing.GetDowncount(), 0);
     }
     u64 GetCNTPCT() override {
-        return Timing::GetTicks();
+        return parent.core_timing.GetTicks();
     }
 
     ARM_Dynarmic& parent;
@@ -172,8 +172,10 @@ void ARM_Dynarmic::Step() {
     cb->InterpreterFallback(jit->GetPC(), 1);
 }
 
-ARM_Dynarmic::ARM_Dynarmic(ExclusiveMonitor& exclusive_monitor, std::size_t core_index)
-    : cb(std::make_unique<ARM_Dynarmic_Callbacks>(*this)), core_index{core_index},
+ARM_Dynarmic::ARM_Dynarmic(Timing::CoreTiming& core_timing, ExclusiveMonitor& exclusive_monitor,
+                           std::size_t core_index)
+    : cb(std::make_unique<ARM_Dynarmic_Callbacks>(*this)), inner_unicorn{core_timing},
+      core_index{core_index}, core_timing{core_timing},
       exclusive_monitor{dynamic_cast<DynarmicExclusiveMonitor&>(exclusive_monitor)} {
     ThreadContext ctx{};
     inner_unicorn.SaveContext(ctx);

src/core/arm/dynarmic/arm_dynarmic.h

@@ -16,6 +16,10 @@ namespace Memory {
 struct PageTable;
 }
 
+namespace Core::Timing {
+class CoreTiming;
+}
+
 namespace Core {
 
 class ARM_Dynarmic_Callbacks;
@@ -23,7 +27,8 @@ class DynarmicExclusiveMonitor;
 
 class ARM_Dynarmic final : public ARM_Interface {
 public:
-    ARM_Dynarmic(ExclusiveMonitor& exclusive_monitor, std::size_t core_index);
+    ARM_Dynarmic(Timing::CoreTiming& core_timing, ExclusiveMonitor& exclusive_monitor,
+                 std::size_t core_index);
     ~ARM_Dynarmic();
 
     void MapBackingMemory(VAddr address, std::size_t size, u8* memory,
@@ -62,6 +67,7 @@ private:
     ARM_Unicorn inner_unicorn;
 
     std::size_t core_index;
+    Timing::CoreTiming& core_timing;
     DynarmicExclusiveMonitor& exclusive_monitor;
 
     Memory::PageTable* current_page_table = nullptr;

src/core/arm/unicorn/arm_unicorn.cpp

@@ -72,7 +72,7 @@ static bool UnmappedMemoryHook(uc_engine* uc, uc_mem_type type, u64 addr, int si
     return {};
 }
 
-ARM_Unicorn::ARM_Unicorn() {
+ARM_Unicorn::ARM_Unicorn(Timing::CoreTiming& core_timing) : core_timing{core_timing} {
     CHECKED(uc_open(UC_ARCH_ARM64, UC_MODE_ARM, &uc));
 
     auto fpv = 3 << 20;
@@ -177,7 +177,7 @@ void ARM_Unicorn::Run() {
     if (GDBStub::IsServerEnabled()) {
         ExecuteInstructions(std::max(4000000, 0));
     } else {
-        ExecuteInstructions(std::max(Timing::GetDowncount(), 0));
+        ExecuteInstructions(std::max(core_timing.GetDowncount(), 0));
     }
 }
 
@@ -190,7 +190,7 @@ MICROPROFILE_DEFINE(ARM_Jit_Unicorn, "ARM JIT", "Unicorn", MP_RGB(255, 64, 64));
 void ARM_Unicorn::ExecuteInstructions(int num_instructions) {
     MICROPROFILE_SCOPE(ARM_Jit_Unicorn);
     CHECKED(uc_emu_start(uc, GetPC(), 1ULL << 63, 0, num_instructions));
-    Timing::AddTicks(num_instructions);
+    core_timing.AddTicks(num_instructions);
     if (GDBStub::IsServerEnabled()) {
         if (last_bkpt_hit) {
             uc_reg_write(uc, UC_ARM64_REG_PC, &last_bkpt.address);

src/core/arm/unicorn/arm_unicorn.h

@@ -9,12 +9,17 @@
 #include "core/arm/arm_interface.h"
 #include "core/gdbstub/gdbstub.h"
 
+namespace Core::Timing {
+class CoreTiming;
+}
+
 namespace Core {
 
 class ARM_Unicorn final : public ARM_Interface {
 public:
-    ARM_Unicorn();
+    explicit ARM_Unicorn(Timing::CoreTiming& core_timing);
     ~ARM_Unicorn();
+
     void MapBackingMemory(VAddr address, std::size_t size, u8* memory,
                           Kernel::VMAPermission perms) override;
     void UnmapMemory(VAddr address, std::size_t size) override;
@@ -43,6 +48,7 @@ public:
 
 private:
     uc_engine* uc{};
+    Timing::CoreTiming& core_timing;
     GDBStub::BreakpointAddress last_bkpt{};
     bool last_bkpt_hit;
 };