[analyzer][Z3][NFC] Use GTEST_SKIP instead of hacks

[steakhal]

Summary

Since @bkramer bumped gtest to 1.10.0 I think it's a good time to clean up some of my hacks.

[steakhal]

now it should build

[Szelethus]

Cheers!

[steakhal]

Introduce the test fixture, and use its setUp() method for implementing this GTEST_SKIP stuff.

[steakhal]

Nothing changed, I'm just retriggering the pre-merge bots as my parent revision landed.

clang/unittests/StaticAnalyzer/FalsePositiveRefutationBRVisitorTest.cpp

 #include "clang/StaticAnalyzer/Core/Checker.h"
 #include "clang/StaticAnalyzer/Core/PathSensitive/CallEvent.h"
 #include "clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h"
 #include "clang/StaticAnalyzer/Frontend/AnalysisConsumer.h"
 #include "clang/StaticAnalyzer/Frontend/CheckerRegistry.h"
 #include "llvm/Config/llvm-config.h"
 #include "gtest/gtest.h"
 
-// FIXME: Use GTEST_SKIP() instead if GTest is updated to version 1.10.0
-#ifdef LLVM_WITH_Z3
-#define SKIP_WITHOUT_Z3
-#else
-#define SKIP_WITHOUT_Z3 return
+// LLVM_ENABLE_Z3_SOLVER will define the LLVM_WITH_Z3 to 1 if finds Z3.
+// Otherwise it will be left undefined.
+#ifndef LLVM_WITH_Z3
+#define LLVM_WITH_Z3 0
 #endif
 
 namespace clang {
 namespace ento {
 namespace {
 
 class FalsePositiveGenerator : public Checker<eval::Call> {
   using Self = FalsePositiveGenerator;

 // C++20 use constexpr below.
 const std::vector<std::string> LazyAssumeArgs{
     "-Xclang", "-analyzer-config", "-Xclang", "eagerly-assume=false"};
 const std::vector<std::string> LazyAssumeAndCrossCheckArgs{
     "-Xclang", "-analyzer-config", "-Xclang", "eagerly-assume=false",
     "-Xclang", "-analyzer-config", "-Xclang", "crosscheck-with-z3=true"};
 
 TEST(FalsePositiveRefutationBRVisitor, UnSatInTheMiddleNoReport) {
-  SKIP_WITHOUT_Z3;
+  if (!LLVM_WITH_Z3)
+    GTEST_SKIP() << "Requires the LLVM_ENABLE_Z3_SOLVER cmake option.";
   constexpr auto Code = R"(
      void reachedWithContradiction();
      void reachedWithNoContradiction();
      void test(int x, int y) {
        if (x * y == 0)
          return;
        reachedWithNoContradiction();
        if (x == 0) {
TEST(FalsePositiveRefutationBRVisitor, UnSatInTheMiddleNoReport) {
   EXPECT_TRUE(runCheckerOnCodeWithArgs<addFalsePositiveGenerator>(
       Code, LazyAssumeArgs, Diags2));
   EXPECT_EQ(Diags2,
             "test.FalsePositiveGenerator:REACHED_WITH_NO_CONTRADICTION\n"
             "test.FalsePositiveGenerator:REACHED_WITH_CONTRADICTION\n");
 }
 
 TEST(FalsePositiveRefutationBRVisitor, UnSatAtErrorNodeWithNewSymbolNoReport) {
-  SKIP_WITHOUT_Z3;
+  if (!LLVM_WITH_Z3)
+    GTEST_SKIP() << "Requires the LLVM_ENABLE_Z3_SOLVER cmake option.";
   constexpr auto Code = R"(
     void reportIfCanBeTrue(bool);
     void reachedWithNoContradiction();
     void test(int x, int y) {
       if (x * y == 0)
        return;
       // We know that 'x * y': {[MIN,-1], [1,MAX]}
       reachedWithNoContradiction();
EXPECT_TRUE(runCheckerOnCodeWithArgs<addFalsePositiveGenerator>(
       Code, LazyAssumeArgs, Diags2));
   EXPECT_EQ(Diags2,
             "test.FalsePositiveGenerator:REACHED_WITH_NO_CONTRADICTION\n"
             "test.FalsePositiveGenerator:CAN_BE_TRUE\n");
 }
 
 TEST(FalsePositiveRefutationBRVisitor,
      UnSatAtErrorNodeDueToRefinedConstraintNoReport) {
-  SKIP_WITHOUT_Z3;
+  if (!LLVM_WITH_Z3)
+    GTEST_SKIP() << "Requires the LLVM_ENABLE_Z3_SOLVER cmake option.";
   constexpr auto Code = R"(
     void reportIfCanBeTrue(bool);
     void reachedWithNoContradiction();
     void test(unsigned x, unsigned n) {
       if (n >= 1 && n <= 2) {
         if (x >= 3)
           return;
         // x: [0,2] and n: [1,2]