Added opcodes for all seven arithmetic operators with K operands
(that is, operands that are numbers in the array of constants of
the function). They cover the cases of constant float operands
(e.g., 'x + .0.0', 'x^0.5') and large integer operands (e.g.,
'x % 10000').
Statements like 'if cond then goto label' generate code so that the
jump in the 'if' goes directly to the given label. This optimization
cannot be done when the jump is backwards leaving the scope of some
variable, as it cannot add the needed 'close' instruction. (The jumps
were already generated by the 'if'.)
This commit also added 'likely'/'unlikely' for tests for errors in
the parser, and it changed the way breaks outside loops are detected.
(Now they are detected like other goto's with undefined labels.)
Added restriction that, when a label is created, there cannot be
another label with the same name visible. That allows backward goto's
to be resolved when they are read. Backward goto's get a close if
they jump out of the scope of some variable; labels get a close only
if previous goto to it jumps out of the scope of some upvalue.
Start of the implementation of "scoped variables" or "to be closed"
variables, local variables whose '__close' (or themselves) are called
when they go out of scope. This commit implements the syntax, the
opcode, and the creation of the corresponding upvalue, but it still
does not call the finalizations when the variable goes out of scope
(the most important part).
Currently, the syntax is 'local scoped name = exp', but that will
probably change.
From the point of view of 'git', all names are relative to the root
directory of the project. So, file names in '$Id:' also should be
relative to that directory: the proper name for test file 'all.lua'
is 'testes/all.lua'.
