cmake: support static linking against libxml2

Author: pavelxdd

Diff for: CMakeLists.txt

@@ -90,6 +90,7 @@ set(ZIG_STATIC_LLVM ${ZIG_STATIC} CACHE BOOL "Prefer linking against static LLVM
 set(ZIG_STATIC_ZLIB ${ZIG_STATIC} CACHE BOOL "Prefer linking against static zlib")
 set(ZIG_STATIC_ZSTD ${ZIG_STATIC} CACHE BOOL "Prefer linking against static zstd")
 set(ZIG_STATIC_CURSES OFF CACHE BOOL "Enable static linking against curses")
+set(ZIG_STATIC_LIBXML2 OFF CACHE BOOL "Enable static linking against libxml2")
 
 if (ZIG_SHARED_LLVM AND ZIG_STATIC_LLVM)
     message(SEND_ERROR "-DZIG_SHARED_LLVM and -DZIG_STATIC_LLVM cannot both be enabled simultaneously")
@@ -167,6 +168,12 @@ if(ZIG_STATIC_CURSES)
     list(APPEND LLVM_LIBRARIES "${CURSES}")
 endif()
 
+if(ZIG_STATIC_LIBXML2)
+    list(REMOVE_ITEM LLVM_LIBRARIES "-lxml2")
+    find_library(LIBXML2 NAMES libxml2.a NAMES_PER_DIR)
+    list(APPEND LLVM_LIBRARIES "${LIBXML2}")
+endif()
+
 find_package(Threads)
 
 set(ZIG_CONFIG_H_OUT "${PROJECT_BINARY_DIR}/config.h")