PowerPC.cpp: No need to explicitly initialize ppcState.

"ppcState{}" is stored in the .data segment, which means the full ~4 MB
is stored in the executable.

"ppcState" is stored in the .bss segment, which means it only stores a
note that tells it to allocate and zero ~4 MB at runtime.

Source/Core/Core/PowerPC/PowerPC.cpp

@@ -32,7 +32,7 @@
 namespace PowerPC
 {
 // STATE_TO_SAVE
-PowerPCState ppcState{};
+PowerPCState ppcState;
 
 static CPUCoreBase* s_cpu_core_base = nullptr;
 static bool s_cpu_core_base_is_injected = false;