feat: Add pkg-config support

- Added support for generating and installing a .pc file for pkg-config
- Controlled by the SENTRY_INSTALL_PKGCONFIG CMake option
- Uses CMAKE_INSTALL_LIBDIR and CMAKE_INSTALL_INCLUDEDIR to support non-standard layouts (e.g., lib64)
- Removed unconditional -lstdc++ to avoid forcing C++ linkage on C projects
- Installs the generated file to the standard pkg-config directory

Author: nmandelblit

CMakeLists.txt

@@ -819,3 +819,30 @@ if(SENTRY_BUILD_SHARED_LIBS)
 	    "$<$<PLATFORM_ID:Android>:-Wl,-z,max-page-size=16384>"
 	)
 endif()
+
+# Generate and install pkg-config file
+if(SENTRY_INSTALL_PKGCONFIG)
+  set(PROJECT_VERSION "${SENTRY_VERSION_FULL}")
+  set(PREFIX "${CMAKE_INSTALL_PREFIX}")
+  include(GNUInstallDirs)
+  # Use absolute paths for libdir and includedir to support non-standard layouts (e.g., lib64)
+  if(IS_ABSOLUTE "${CMAKE_INSTALL_LIBDIR}")
+    set(PKGCONFIG_LIBDIR "${CMAKE_INSTALL_LIBDIR}")
+  else()
+    set(PKGCONFIG_LIBDIR "\${prefix}/${CMAKE_INSTALL_LIBDIR}")
+  endif()
+  if(IS_ABSOLUTE "${CMAKE_INSTALL_INCLUDEDIR}")
+    set(PKGCONFIG_INCLUDEDIR "${CMAKE_INSTALL_INCLUDEDIR}")
+  else()
+    set(PKGCONFIG_INCLUDEDIR "\${prefix}/${CMAKE_INSTALL_INCLUDEDIR}")
+  endif()
+  configure_file(
+    "${CMAKE_CURRENT_SOURCE_DIR}/sentry.pc.in"
+    "${CMAKE_CURRENT_BINARY_DIR}/sentry.pc"
+    @ONLY
+  )
+  install(
+    FILES "${CMAKE_CURRENT_BINARY_DIR}/sentry.pc"
+    DESTINATION "${CMAKE_INSTALL_LIBDIR}/pkgconfig"
+  )
+endif()

sentry.pc.in

@@ -0,0 +1,11 @@
+prefix=@PREFIX@
+exec_prefix=${prefix}
+libdir=@PKGCONFIG_LIBDIR@
+includedir=@PKGCONFIG_INCLUDEDIR@
+
+Name: sentry
+Description: Sentry SDK for C, C++ and native applications
+Version: @PROJECT_VERSION@
+URL: https://sentry.io/
+Libs: -L${libdir} -lsentry
+Cflags: -I${includedir}