Test is too non portable. (For instance, it does not work for
different number types.)

Old Microsoft compilers do not support those casts.

Registry field "LUA_NOENV" (that signals to libraries that option -E
is on) now part of the "official" API of Lua stand-alone.

We may want to add other string variants in the future; this change
documents better where the code may need to handle those variants.

The few UTF-8 test files are commented as such, and there is only one
non UTF-8 test file (to test non UTF-8 sources).

Took the opportunity and moved the code that controls call hooks
in 'luaV_execute' into a function.

Although stack resize can be a little expensive, it seems unusual to
have too many threads needing resize during one GC cycle. On the other
hand, the change allows full collections to skip the propagate phase,
going straight from a pause to the atomic phase.

String rendering now derived from the numeric original definitions.

Equality according to 'strcoll' does not imply that strings have
the same length.

Several functions that were already being used only inside their
own file have been declared as 'static'.

Like 'require', the command-line option '-l' discards an optional
version suffix (everything after an hyphen) from a file name when
creating the module name.

- Better comments about short strings in opcodes.
- luaH_newkey made static.

'lua_resetthread' is back to its original signature, to avoid
incompatibilities in the ABI between releases of the same version.
New function 'lua_closethread' added with the "correct" signature.

Typos in comments and details in the manual.

Also, small tweak in makefile. (-Wsign-compare is already enabled by
-Wextra.)

The size of the list of upvalue names are stored separated from the
size of the list of upvalues, but they share the same array.

Comments in 'onelua.c'

We still need access to a 16-bit system to correctly test
these changes.

It also causes 'L->top' to be wrong when the error happens,
triggering an 'assert'.

There is no need for those intermediate definitions.

Do not try to detect automatically whether system is iOS; it is
simpler and more reliable to let the programmer inform that.

When converting from pointer to integer, use 'uintptr_t' if available;
otherwise try 'uintmax_t', and use 'size_t' as last resource.

Despite claiming to be ISO, the C library in some Apple platforms
does not implement 'system'.

Test files are more polite regarding the use of globals when locals
would do, and when globals are necessary deleting them after use.

Everything depends on the Lua version (as given by 'lua.h')

Reuse macros for objects when defining the macros for values.

Added some auxiliary macros + fixed a bug in compilation option
EMERGENCYGCTESTS. (It should not try to force an emergency collection
when it cannot run one.)

Identifier LUA_NUMTAGS was deprecated (changed to LUA_NUMTYPES) +
better handling of some inclusion loops.