Fixed compilation in GCC 7 (#1301)

CMakeLists.txt

@@ -309,4 +309,3 @@ IF (UNIX) # TODO: port to windows
  INSTALL(TARGETS wasm-reduce DESTINATION ${CMAKE_INSTALL_BINDIR})
 
 ENDIF()
-

src/tools/fuzzing.h

@@ -671,7 +671,7 @@ class TranslateToFuzzReader {
  hangStack.push_back(nullptr);
  condition = makeCondition();
  }
- // we need to find a proper target to break to; try a few times 
+ // we need to find a proper target to break to; try a few times
  int tries = TRIES;
  while (tries-- > 0) {
  auto* target = vectorPick(breakableStack);
@@ -1352,12 +1352,26 @@ class TranslateToFuzzReader {
  return first;
  }
 
+ // Trick to avoid a bug in GCC 7.x.
+ // Upstream bug report: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82800
+ #define GCC_VERSION (__GNUC__ * 10000 \
+ + __GNUC_MINOR__ * 100 \
+ + __GNUC_PATCHLEVEL__)
+ #if GCC_VERSION > 70000 && GCC_VERSION < 70300
+ #pragma GCC diagnostic push
+ #pragma GCC diagnostic ignored "-Wmaybe-uninitialized"
+ #endif
+
  template<typename T, typename... Args>
  T pickGivenNum(size_t num, T first, Args... args) {
  if (num == 0) return first;
  return pickGivenNum<T>(num - 1, args...);
  }
 
+ #if GCC_VERSION > 70000 && GCC_VERSION < 70300
+ #pragma GCC diagnostic pop
+ #endif
+
  // utilities
 
  Name getTargetName(Expression* target) {