This fix is a follow up on the fix for similar issue 56761.
When sanitizing data read from the events_waits_history_long table,
the code needs also to sanitize the schema_name / object_name / file_name pointers,
because such pointers could also hold invalid values.
Checking the string length alone was required but not sufficient.
This fix verifies that:
- the table schema and table name used in table io events
- the file name used in file io events
are valid pointers before dereferencing these pointers.
Fix various mismatches between function's language linkage. Any
particular function that is declared in C++ but should be callable
from C must have C linkage. Note that function types with different
linkages are also distinct. Thus, if a function type is declared in
C code, it will have C linkage (same if declared in a extern "C"
block).
