[CI]Added initial framework of CXX unittest (#98)

Based on the discussion in #53 , I just added the initial flow of CXX unittests for this repo, with providing two dummy UTs as placeholder to show the usage, feel free to add your own CXX unittests. 
@Superjomn  @ptillet 

@ptillet , in this PR, I also configure the integration-tests.yml to add the unittest into github CI check. 

Thanks

unittest/Analysis/CMakeLists.txt

@@ -0,0 +1,5 @@
+add_triton_ut(
+  NAME TritonAnalysisTests
+  SRCS UtilityTest.cpp
+  LIBS TritonAnalysis
+)

unittest/Analysis/UtilityTest.cpp

@@ -0,0 +1,14 @@
+//===- UtilityTest.cpp - Tests for
+// Utility----------------------------------===//
+//
+//===----------------------------------------------------------------------===//
+
+#include "triton/Analysis/Utility.h"
+#include <gmock/gmock.h>
+#include <gtest/gtest.h>
+
+namespace mlir {
+
+TEST(UtilityTest, DummyTest) { EXPECT_EQ(true, true); }
+
+} // namespace mlir

unittest/CMakeLists.txt

@@ -0,0 +1,27 @@
+
+include (${CMAKE_CURRENT_SOURCE_DIR}/googletest.cmake)
+
+include(GoogleTest)
+enable_testing()
+
+function(add_triton_ut)
+  set(options)
+  set(oneValueArgs NAME)
+  set(multiValueArgs SRCS LIBS)
+  cmake_parse_arguments(_ "${options}" "${oneValueArgs}" "${multiValueArgs}" ${ARGN})
+  add_test(NAME ${__NAME}
+          COMMAND ${__NAME})
+  add_executable(
+          ${__NAME}
+          ${__SRCS})
+  target_link_libraries(
+          ${__NAME}
+          GTest::gtest_main
+          gmock
+          ${__LIBS})
+
+  gtest_discover_tests(${__NAME})
+endfunction()
+
+add_subdirectory(Analysis)
+add_subdirectory(Conversion)

unittest/Conversion/CMakeLists.txt

@@ -0,0 +1 @@
+add_subdirectory(TritonGPUToLLVM)

unittest/Conversion/TritonGPUToLLVM/CMakeLists.txt

@@ -0,0 +1,5 @@
+add_triton_ut(
+	NAME TritonGPUToLLVMTests
+	SRCS TritonGPUToLLVMTests.cpp
+	LIBS TritonGPUToLLVM
+)

unittest/Conversion/TritonGPUToLLVM/TritonGPUToLLVMTests.cpp

@@ -0,0 +1,14 @@
+//===- TritonGPUToLLVMTests.cpp - Tests for
+// TritonGPUToLLVM----------------------------------===//
+//
+//===----------------------------------------------------------------------===//
+
+#include "triton/Conversion/TritonGPUToLLVM/PtxAsmFormat.h"
+#include <gmock/gmock.h>
+#include <gtest/gtest.h>
+
+namespace mlir {
+
+TEST(PtxAsmFormatTest, BasicTest) { EXPECT_EQ(true, true); }
+
+} // namespace mlir

unittest/googletest.cmake

@@ -0,0 +1,23 @@
+include(FetchContent)
+
+set(GOOGLETEST_DIR "" CACHE STRING "Location of local GoogleTest repo to build against")
+
+if(GOOGLETEST_DIR)
+  set(FETCHCONTENT_SOURCE_DIR_GOOGLETEST ${GOOGLETEST_DIR} CACHE STRING "GoogleTest source directory override")
+endif()
+
+FetchContent_Declare(
+  googletest
+  GIT_REPOSITORY https://github.com/google/googletest.git
+  GIT_TAG release-1.12.1
+  )
+
+FetchContent_GetProperties(googletest)
+
+if(NOT googletest_POPULATED)
+  FetchContent_Populate(googletest)
+  if (MSVC)
+    set(gtest_force_shared_crt ON CACHE BOOL "" FORCE)
+  endif()
+  add_subdirectory(${googletest_SOURCE_DIR} ${googletest_BINARY_DIR} EXCLUDE_FROM_ALL)
+endif()