MIPS: port Simplify handling of exits from with and catch.

MIPS: port Simplify handling of exits from with and catch.

Ported r8922 (5ea2fb5)

Original commit message:
Remove the try/finally used for with and catch. Instead of using
try/finally to handle break and continue from with or catch,
statically track nesting dept and clean up when compiling break or
continue.
And instead of using try/finally to handle throw to handler in a frame
whose pc is inside a with or catch, store the context that the handler
should run in in the handler itself.

BUG=
TEST=

Committed: http://code.google.com/p/v8/source/detail?r=8936

[Kevin Millikin (Chromium), 2011-08-16 08:42:14]

LGTM.  I will land it.

http://codereview.chromium.org/7648026/diff/1/src/mips/macro-assembler-mips.cc
File src/mips/macro-assembler-mips.cc (right):

http://codereview.chromium.org/7648026/diff/1/src/mips/macro-assembler-mips.c...
src/mips/macro-assembler-mips.cc:2281: li(t0, Operand(StackHandler::ENTRY));
StackHandler::ENTRY is zero.  If you wanted to rely on that (with a static
assert), you could avoid the load here.