GH-2919: Prevent tuple constants that compare equal but have different item types from being merged into one.

At module cleanup time, clear the module dict before the global references that its content might still be using.

Keep owned references to builtins module, "cython_runtime" module and preimport module to prevent crashes when they get removed from sys.modules. Generate cleanup code for them in the end.
Closes #2885.

Closes GH-2884.

Issue a warning when casting a GIL-requiring function into a nogil function (which breaks GIL validation).
Closes GH-2879.

See #2879.

Refactor parsing function in code coverage plugin to split the actual parsing code from the lookup code.

Exclude non-executable lines from coverage analysis (anything that does not generate a line trace call).

GH-1461: Include the signature line of cdef functions in the import-time line tracing and coverage report.

GH-1461: Include the signature line of cdef functions in the import-time line tracing and coverage report.

This reverts commit d49062fd.

When detecting an invalid system configuration for overflow checks, at least print a warning, instead of leaving a dangling live exception behind.

This fixes Github issue #2819.

Closes #1470.

Closes GH-2845.

GCC diagnostic pragmas were introduced in GCC 4.6, so augment the GCC
compiler check with a version check to avoid compilation errors with GCC
< 4.6.

Add safety cast in queue tutorial code that avoids casting a potentially non-pointer-sized "int" to a "void*".

Silence an "unused" C compiler warning when we cannot easily decide whether to include the "__Pyx_Method_ClassMethod" utility code or not.

Add safety parentheses in helper macro, also to avoid a compiler warning about tautological comparisons.