[cmake, deps] conjure common/httplib.h and remove global def for httplib macros (#3800)

httplib stuff done by @crueter on #3797

+ some extra stuff since the warning push/pop should be in header i fear :)

Signed-off-by: lizzie <lizzie@eden-emu.dev>

Co-authored-by: crueter <crueter@eden-emu.dev>
Reviewed-on: https://git.eden-emu.dev/eden-emu/eden/pulls/3800
Reviewed-by: crueter <crueter@eden-emu.dev>
Co-authored-by: lizzie <lizzie@eden-emu.dev>
Co-committed-by: lizzie <lizzie@eden-emu.dev>

src/common/CMakeLists.txt

@@ -146,7 +146,8 @@ add_library(
     zstd_compression.cpp
     zstd_compression.h
     fs/ryujinx_compat.h fs/ryujinx_compat.cpp
-    fs/symlink.h fs/symlink.cpp)
+    fs/symlink.h fs/symlink.cpp
+    httplib.h)
 
 if(WIN32)
     target_sources(common PRIVATE windows/timer_resolution.cpp
@@ -244,7 +245,7 @@ else()
     target_link_libraries(common PUBLIC Boost::headers)
 endif()
 
-target_link_libraries(common PUBLIC Boost::filesystem Boost::context)
+target_link_libraries(common PUBLIC Boost::filesystem Boost::context httplib::httplib)
 
 if (lz4_ADDED)
     target_include_directories(common PRIVATE ${lz4_SOURCE_DIR}/lib)

src/common/httplib.h

@@ -0,0 +1,18 @@
+// SPDX-FileCopyrightText: Copyright 2026 Eden Emulator Project
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+#pragma once
+
+#define CPPHTTPLIB_DISABLE_MACOSX_AUTOMATIC_ROOT_CERTIFICATES 1
+#define CPPHTTPLIB_OPENSSL_SUPPORT 1
+
+#ifdef __GNUC__
+#pragma GCC diagnostic push
+#ifndef __clang__
+#pragma GCC diagnostic ignored "-Wmaybe-uninitialized"
+#endif
+#endif
+#include <httplib.h>
+#ifdef __GNUC__
+#pragma GCC diagnostic pop
+#endif