fix include/namespace related compilation errors (#7019)

a user on discord reported compilation errors when trying to compile
on Linux with GCC 13 and Clang 16.

src/audio_core/time_stretch.cpp

@@ -10,8 +10,10 @@
 #include <type_traits>
 #include <vector>
 #include <SoundTouch.h>
+
 #include "audio_core/audio_types.h"
 #include "audio_core/time_stretch.h"
+#include "common/assert.h"
 #include "common/logging/log.h"
 
 namespace AudioCore {

src/tests/audio_core/hle/adts_reader.cpp

@@ -3,6 +3,8 @@
 // Refer to the license.txt file included.
 
 #include <catch2/catch_test_macros.hpp>
+#include <fmt/format.h>
+
 #include "audio_core/hle/adts.h"
 
 namespace {

src/tests/audio_core/hle/hle.cpp

@@ -3,6 +3,8 @@
 // Refer to the license.txt file included.
 
 #include <catch2/catch_test_macros.hpp>
+#include <fmt/core.h>
+
 #include "audio_core/hle/decoder.h"
 #include "audio_core/hle/hle.h"
 #include "audio_core/lle/lle.h"

src/tests/audio_core/lle/lle.cpp

@@ -3,6 +3,8 @@
 // Refer to the license.txt file included.
 
 #include <catch2/catch_test_macros.hpp>
+#include <fmt/core.h>
+
 #include "audio_core/hle/decoder.h"
 #include "audio_core/lle/lle.h"
 #include "common/common_paths.h"

src/video_core/renderer_opengl/gl_state.cpp

@@ -344,7 +344,7 @@ void OpenGLState::Apply() const {
 
     // Clip distance
     if (!GLES || GLAD_GL_EXT_clip_cull_distance) {
-        for (size_t i = 0; i < clip_distance.size(); ++i) {
+        for (std::size_t i = 0; i < clip_distance.size(); ++i) {
             if (clip_distance[i] != cur_state.clip_distance[i]) {
                 if (clip_distance[i]) {
                     glEnable(GL_CLIP_DISTANCE0 + static_cast<GLenum>(i));