Adding pugixml version 1.8.1

ports/pugixml/CONTROL

@@ -0,0 +1,3 @@
+Source: pugixml
+Version: 1.8.1
+Description: C++ XML processing library

ports/pugixml/portfile.cmake

@@ -0,0 +1,28 @@
+include(vcpkg_common_functions)
+set(SOURCE_PATH ${CURRENT_BUILDTREES_DIR}/src/pugixml-1.8)
+vcpkg_download_distfile(ARCHIVE
+    URLS "https://github.com/zeux/pugixml/releases/download/v1.8.1/pugixml-1.8.1.zip"
+    FILENAME "pugixml-1.8.1.zip"
+    SHA512 683fe224a9bcac032d78cb44d03915a3766d2faa588f3a8486b5719f26eeba3e17d447edf70e1907f51f8649ffb4607b6badd1365e4c15cf24279bf577dc853e
+)
+vcpkg_extract_source_archive(${ARCHIVE})
+
+vcpkg_apply_patches(
+    SOURCE_PATH ${SOURCE_PATH}
+    PATCHES
+        ${CMAKE_CURRENT_LIST_DIR}/pugixmlapi.patch
+)
+
+vcpkg_configure_cmake(
+    SOURCE_PATH ${SOURCE_PATH}
+	OPTIONS
+        -DBUILD_DEFINES="PUGIXML_API=__declspec\(dllexport\)"
+)
+
+vcpkg_install_cmake()
+vcpkg_copy_pdbs()
+
+file(REMOVE_RECURSE ${CURRENT_PACKAGES_DIR}/lib/cmake)
+file(REMOVE_RECURSE ${CURRENT_PACKAGES_DIR}/debug/lib/cmake)
+file(REMOVE_RECURSE ${CURRENT_PACKAGES_DIR}/debug/include)
+file(INSTALL ${SOURCE_PATH}/readme.txt DESTINATION ${CURRENT_PACKAGES_DIR}/share/pugixml RENAME copyright)

ports/pugixml/pugixmlapi.patch

@@ -0,0 +1,13 @@
+diff --git a/src/pugixml.hpp b/src/pugixml.hpp
+index 4d76bfa..75a4f8a 100644
+--- a/src/pugixml.hpp
++++ b/src/pugixml.hpp
+@@ -50,7 +50,7 @@
+ 
+ // If no API is defined, assume default
+ #ifndef PUGIXML_API
+-#	define PUGIXML_API
++#	define PUGIXML_API __declspec(dllimport)
+ #endif
+ 
+ // If no API for classes is defined, assume default