[except] Complete dissolving this clause into the rest of the standard

Author: AlisdairM

source/support.tex

@@ -3760,6 +3760,15 @@
 \pnum
 The header \libheaderdef{exception}
 defines several types and functions related to the handling of exceptions in a \Cpp{} program.
+The function \tcode{std::terminate}\iref{except.terminate}
+is used by the exception
+handling mechanism for coping with errors related to the exception handling
+mechanism itself.
+The function \tcode{std::uncaught_exceptions}\iref{uncaught.exceptions}
+reports how many exceptions are uncaught in the current thread.
+The function \tcode{std::current_exception}\iref{propagation} and the class
+\tcode{std::nested_exception}\iref{except.nested} can be used by a program to
+capture the currently handled exception.
 
 \rSec2[exception.syn]{Header \tcode{<exception>} synopsis}