Shares TESTANY, TESTALL, and BUFFER_SIZE_ELEMENTS and related defines,
in dr_project_wide_defines.h, eliminating duplication in many places.
Removes ext/ext_utils.h which becomes empty after this change.
Issue: #8001
The drsyms DynamoRIO Extension provides
symbol information. Currently drsyms supports reading symbol information from Windows PDB
files or Linux ELF, Mac Mach-O, or from Windows PECOFF files with DWARF2 line information.