Fix inconsistent class/struct usage

src/allocator.cpp

@@ -47,7 +47,7 @@ namespace randomx {
 		rx_aligned_free(ptr);
 	}
 
-	template class AlignedAllocator<CacheLineSize>;
+	template struct AlignedAllocator<CacheLineSize>;
 
 	void* LargePageAllocator::allocMemory(size_t count) {
 		return allocLargePagesMemory(count);

src/jit_compiler_a64.hpp

@@ -38,7 +38,7 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 namespace randomx {
 
 	class Program;
-	class ProgramConfiguration;
+	struct ProgramConfiguration;
 	class SuperscalarProgram;
 	class Instruction;
 

src/jit_compiler_fallback.hpp

@@ -36,7 +36,7 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 namespace randomx {
 
 	class Program;
-	class ProgramConfiguration;
+	struct ProgramConfiguration;
 	class SuperscalarProgram;
 
 	class JitCompilerFallback {

src/jit_compiler_x86.hpp

@@ -36,7 +36,7 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 namespace randomx {
 
 	class Program;
-	class ProgramConfiguration;
+	struct ProgramConfiguration;
 	class SuperscalarProgram;
 	class JitCompilerX86;
 	class Instruction;