First step in refactoring hydrogen control instructions.

First step in refactoring hydrogen control instructions.

This change changes the internal data structure of HControlInstruction
and introduced an iterator interface to enumerate all successors of a block.

It also saves allocation space by only allocating so many successor blocks as needed
for each instruction.

Next step is to allow HControlInstructions with >2 successors.

[fschneider, 2011-05-25 12:35:40]

Added iterator interface + refactored code to use it.

[Kevin Millikin (Chromium), 2011-05-25 15:50:28]

Quick comment, I'll look more closely later.

http://codereview.chromium.org/7008011/diff/5001/src/hydrogen-instructions.h
File src/hydrogen-instructions.h (right):

http://codereview.chromium.org/7008011/diff/5001/src/hydrogen-instructions.h#...
src/hydrogen-instructions.h:793: template<typename T, int NumElements>
We have more or less this class "OperandContainer" in the lithium-xxx.h files,
and we also have "HOperandContainer" which is just specialized to HValue*.

You should just add an EmbeddedContainer class to utils.h, I think.