Merge ElementsProject#1001: Adds an -fno-stack-check compile time fla…

…g to OSX local builds

43657b5 Adds an -fno-stack-check compile time flag to OSX local builds (Mike Slominsk)

Pull request description:

  As a workaround for several elements issues on OSX 10.15 and later, this PR adds the `-fno-stack-check` flag to local (non-cross compile) OSX builds.

  Background: There seems to be a general issue with OSX (version >= 10.15) builds and clang's default use of `-fstack-check` which seems to be buggy enough to cause issues with multiple projects.

  closes ElementsProject#987 ElementsProject#998
  Also related to ElementsProject#782

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Tree-SHA512: b8ecf10771da235878d10a59cddf22be9e587c2c6b278a62ea777d547b1a37abfbec4945842df2b581407e81dafcfc3df1d86e27f861a03322cb188917a5e940

configure.ac

@@ -667,6 +667,8 @@ case $host in
            PKG_CONFIG_PATH="$qt5_prefix/lib/pkgconfig:$PKG_CONFIG_PATH"
            export PKG_CONFIG_PATH
          fi
+         dnl On some versions of osx stack check is turned on by default and is broken
+         AX_CHECK_COMPILE_FLAG([-fno-stack-check],[HARDENED_CXXFLAGS="$HARDENED_CXXFLAGS -fno-stack-check"])
        fi
      else
        case $build_os in