Bad-sounding schur.cc compilation warnings.

[Daniel J Sebald]

I saw the following warnings during compilation.  They look kind of 
troublesome:

/home/sebald/octave/octave/octave/liboctave/numeric/schur.cc: In member 
function 'octave_idx_type schur<T>::init(const T&, const string&, bool) 
[with T = Matrix; octave_idx_type = int; std::string = 
std::basic_string<char>]':
/home/sebald/octave/octave/octave/liboctave/numeric/schur.cc:176:19: 
warning: variable 'selector' might be clobbered by 'longjmp' or 'vfork' 
[-Wclobbered]
   double_selector selector = 0;
                   ^
/home/sebald/octave/octave/octave/liboctave/numeric/schur.cc: In member 
function 'octave_idx_type schur<T>::init(const T&, const string&, bool) 
[with T = FloatMatrix; octave_idx_type = int; std::string = 
std::basic_string<char>]':
/home/sebald/octave/octave/octave/liboctave/numeric/schur.cc:265:18: 
warning: variable 'selector' might be clobbered by 'longjmp' or 'vfork' 
[-Wclobbered]
   float_selector selector = 0;
                  ^
/home/sebald/octave/octave/octave/liboctave/numeric/schur.cc: In member 
function 'octave_idx_type schur<T>::init(const T&, const string&, bool) 
[with T = ComplexMatrix; octave_idx_type = int; std::string = 
std::basic_string<char>]':
/home/sebald/octave/octave/octave/liboctave/numeric/schur.cc:354:20: 
warning: variable 'selector' might be clobbered by 'longjmp' or 'vfork' 
[-Wclobbered]
   complex_selector selector = 0;
                    ^
/home/sebald/octave/octave/octave/liboctave/numeric/schur.cc: In member 
function 'octave_idx_type schur<T>::init(const T&, const string&, bool) 
[with T = FloatComplexMatrix; octave_idx_type = int; std::string = 
std::basic_string<char>]':
/home/sebald/octave/octave/octave/liboctave/numeric/schur.cc:463:26: 
warning: variable 'selector' might be clobbered by 'longjmp' or 'vfork' 
[-Wclobbered]
   float_complex_selector selector = 0;

Dan