gcc emits `Wsubobject-linkage`, because the the publicly visible
`TablePrinter` contains `ColumnInfo`, which is part of an anonymous
namespace

Classes will automatically inherit the virtual-ness of their base
class destructors. If the base class already has a virtual
destructor and the derived class needs default destructor semantics
then the derived class can omit defining the destructor in favor of
the compiler automatically defining it.

This has an additional benefit of reenabling move semantics. The
presence of a user-specified destructor automatically disables move
operations.

This is the recommended way of adding new Opts in our documentation
for using custom main, but we did not compile the code to see if it
works. We now compile the example as part of the BUILD_EXAMPLES
option.

Fixes #2787

* Alter meson for Android cross builds.

* Handle liblog linking on Termux as well as the Android NDK.

Make compiler flags for reproducible builds optional

no change in default behavior: -ffile-prefix-map is still added if
supported by compiler but add option for disabling it as it breaks
generic tools for extracting debuginfo/debugsource from build artifacts
like: https://sourceware.org/git/?p=debugedit.git;a=blob;f=scripts/find-debuginfo.in