tools/tracer: fails to build with libc++

[jbeich]

Steps to reproduce

$ export CC=clang CXX=clang++ CXXFLAGS="$CXXFLAGS -stdlib=libc++" LDFLAGS="$LDFLAGS -fuse-ld=bfd"
$ cmake -DBUILD_TOOLS=ON -B /tmp/MediaSDK_build -G Ninja
$ cmake --build /tmp/MediaSDK_build

Clang 10

tools/tracer/dumps/dump.h:175:42: error: dynamic_cast from rvalue to reference type 'std::ostringstream &' (aka 'basic_ostringstream<char> &')
        str += "* " + structName + "=" + ToHexFormatString(_struct) + "\n";
                                         ^~~~~~~~~~~~~~~~~~~~~~~~~~
tools/tracer/dumps/dump.h:81:37: note: expanded from macro 'ToHexFormatString'
    #define ToHexFormatString( x ) (dynamic_cast< std::ostringstream & >( ( std::ostringstream() << std::hex << pVoidToHexString((void*)x) ) ).str() )
                                    ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
tools/tracer/dumps/dump.h:182:42: error: dynamic_cast from rvalue to reference type 'std::ostringstream &' (aka 'basic_ostringstream<char> &')
        str += "* " + structName + "=" + ToHexFormatString(_struct) + "\n";
                                         ^~~~~~~~~~~~~~~~~~~~~~~~~~
tools/tracer/dumps/dump.h:81:37: note: expanded from macro 'ToHexFormatString'
    #define ToHexFormatString( x ) (dynamic_cast< std::ostringstream & >( ( std::ostringstream() << std::hex << pVoidToHexString((void*)x) ) ).str() )
                                    ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
tools/tracer/dumps/dump.h:200:56: error: dynamic_cast from rvalue to reference type 'std::ostringstream &' (aka 'basic_ostringstream<char> &')
                    name = structName + ".ExtParam[" + ToString(i) + "]";
                                                       ^~~~~~~~~~~
tools/tracer/dumps/dump.h:70:28: note: expanded from macro 'ToString'
    #define ToString( x )  dynamic_cast< std::ostringstream & >( \
                           ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
tools/tracer/dumps/dump.h:490:67: error: dynamic_cast from rvalue to reference type 'std::ostringstream &' (aka 'basic_ostringstream<char> &')
                    str += "WARNING: Can't read from ExtParam[" + ToString(i) + "]!\n";
                                                                  ^~~~~~~~~~~
tools/tracer/dumps/dump.h:70:28: note: expanded from macro 'ToString'
    #define ToString( x )  dynamic_cast< std::ostringstream & >( \
                           ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
tools/tracer/dumps/dump.cpp:370:23: error: dynamic_cast from rvalue to reference type 'std::ostringstream &' (aka 'basic_ostringstream<char> &')
        name += "(" + ToString(io) + ")";
                      ^~~~~~~~~~~~
tools/tracer/dumps/dump.h:70:28: note: expanded from macro 'ToString'
    #define ToString( x )  dynamic_cast< std::ostringstream & >( \
                           ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
5 errors generated.

GCC 10

In file included from tools/tracer/dumps/dump.cpp:31:
tools/tracer/dumps/dump.h: In member function 'std::__1::string DumpContext::dump(std::__1::string, const void*)':
tools/tracer/dumps/dump.h:81:37: error: invalid 'static_cast' from type 'std::__1::basic_ostringstream<char>' to type 'std::__1::ostringstream&' {aka 'std::__1::basic_ostringstream<char>&'}
   81 |     #define ToHexFormatString( x ) (dynamic_cast< std::ostringstream & >( ( std::ostringstream() << std::hex << pVoidToHexString((void*)x) ) ).str() )
      |                                     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
tools/tracer/dumps/dump.h:182:42: note: in expansion of macro 'ToHexFormatString'
  182 |         str += "* " + structName + "=" + ToHexFormatString(_struct) + "\n";
      |                                          ^~~~~~~~~~~~~~~~~
In file included from tools/tracer/dumps/dump.cpp:31:
tools/tracer/dumps/dump.cpp: In function 'std::__1::string GetIOPattern(mfxU32)':
tools/tracer/dumps/dump.h:70:28: error: invalid 'static_cast' from type 'std::__1::basic_ostringstream<char>' to type 'std::__1::ostringstream&' {aka 'std::__1::basic_ostringstream<char>&'}
   70 |     #define ToString( x )  dynamic_cast< std::ostringstream & >( \
      |                            ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   71 |         ( std::ostringstream() << std::dec << x ) ).str()
      |         ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
tools/tracer/dumps/dump.cpp:370:23: note: in expansion of macro 'ToString'
  370 |         name += "(" + ToString(io) + ")";
      |                       ^~~~~~~~