Subdirectories:
abi Tests for ABI compatibility -- mangling, object layout, etc.
-compat Tests for binary compatibility (consistency, not ABI conformance)
+bprob Tests for functionality of profile-directed block ordering.
+compat Tests for binary compatibility (consistency, not ABI conformance).
cpp Tests for the preprocessor.
+debug Tests for debugging options.
eh Tests for exception handling.
expr Tests for expressions.
ext Tests for GNU language extensions.
+gcov Tests for GCOV (code coverage) support.
inherit Tests for inheritance -- virtual functions, multiple inheritance, etc.
init Tests for initialization semantics, constructors/destructors, etc.
lookup Tests for lookup semantics, namespaces, using, etc.
+opt Tests for fixes of bugs with particular optimizations.
+other Tests that don't quite fit anywhere else.
overload Tests for overload resolution and conversions.
parse Tests for parsing.
rtti Tests for run-time type identification (typeid, dynamic_cast, etc.)
+special Tests requiring individual processing.
template Tests for templates.
+tls Tests for support of thread-local data.
warn Tests for compiler warnings.
other Tests that don't fit into one of the other categories.