Fix bashism in `libsanitizer/configure.tgt'

Appending to a string variable with `+=' is a bashism and does not work in
strict POSIX shells like dash.  This results in the extra compilation flags not
to be set correctly.  This patch replaces the `+=' syntax with a simple string
interpolation to append to the `EXTRA_CXXFLAGS' variable.

libsanitizer/ChangeLog

	PR sanitizer/101111
	* configure.tgt: Fix bashism in setting of `EXTRA_CXXFLAGS'.
1 file changed