[gemmlowp] create a new port (#20403)

* [gemmlowp] create a new port

* update baseline JSON

* [gemmlowp] support find_pacakge

* export `unofficial::` targets

* [gemmlowp] add HEAD_REF

* [gemmlowp] use latest sources

* remove patches to support find_package

ports/gemmlowp/portfile.cmake

@@ -0,0 +1,22 @@
+if(NOT VCPKG_TARGET_IS_WINDOWS)
+    vcpkg_check_linkage(ONLY_DYNAMIC_LIBRARY)
+endif()
+
+vcpkg_from_github(
+    OUT_SOURCE_PATH SOURCE_PATH
+    REPO google/gemmlowp
+    REF daf630d3d0c439dbe22229838a5ba1bc5f82908d
+    SHA512 8d1a422bbf2495dcec1c30147bc96d0a2ca494220a45050937f84567c3352cd8916f07d1bbab68c8d36ae7ce3e9b8bee8b518900e21967a3185bf7ff25812785
+    HEAD_REF master
+)
+
+vcpkg_cmake_configure(
+    SOURCE_PATH "${SOURCE_PATH}/contrib"
+    OPTIONS
+        -DBUILD_TESTING=OFF
+)
+vcpkg_cmake_install()
+vcpkg_cmake_config_fixup(CONFIG_PATH "lib/cmake/${PORT}")
+
+file(INSTALL "${SOURCE_PATH}/LICENSE" DESTINATION "${CURRENT_PACKAGES_DIR}/share/${PORT}" RENAME copyright)
+file(REMOVE_RECURSE "${CURRENT_PACKAGES_DIR}/debug/include")

ports/gemmlowp/vcpkg.json

@@ -0,0 +1,17 @@
+{
+  "name": "gemmlowp",
+  "version-date": "2021-09-28",
+  "description": "Low-precision matrix multiplication",
+  "homepage": "https://github.com/google/gemmlowp",
+  "license": "Apache-2.0",
+  "dependencies": [
+    {
+      "name": "vcpkg-cmake",
+      "host": true
+    },
+    {
+      "name": "vcpkg-cmake-config",
+      "host": true
+    }
+  ]
+}

versions/baseline.json

@@ -2336,6 +2336,10 @@
       "baseline": "2.42.2",
       "port-version": 1
     },
+    "gemmlowp": {
+      "baseline": "2021-09-28",
+      "port-version": 0
+    },
     "genann": {
       "baseline": "2019-07-10",
       "port-version": 1

versions/g-/gemmlowp.json

@@ -0,0 +1,9 @@
+{
+  "versions": [
+    {
+      "git-tree": "843bf152a690b01de4606a68a769e67e8d1ca6bf",
+      "version-date": "2021-09-28",
+      "port-version": 0
+    }
+  ]
+}