Merge pull request !1082 from hewei/support_cont_break

Merge pull request !1107 from gengdongjie/master

Merge pull request !1114 from casgj/gaojing

Merge pull request !1112 from seatea/fix-sgd-weight-decay-bug

To handle 'break' and 'continue' statement, a loop context is pushed
to a stack before we parse the loop body, and pop it after body parsed.
When a 'break', 'continue' statement is encountered, we retrieve current
loop contex from the stack, and let the current block jump to the end
block or header block;

For 'break' statement, we added an extra 'end_block' follow the 'after_block',
because 'after_block' is called from a ContionalJump in 'header_block', it can
not be set as jump target from other place. to support 'break', we let loop
body jump to the 'end_block' at the 'break' point. and 'after_block'
maybe a good place to handle loop 'else' clause in the future.

Handle 'pass' is simple, just bypass it when doing parse.

Merge pull request !1096 from SanjayChan/03cell

Merge pull request !1110 from lichen/fix_gatherv2_and_dataset_bug

Weight decay has been considered and caculated in `SGD` operation, so
there's no need to apply weight decay in `SGD` optimizer.

Merge pull request !1099 from fary86/fix_bug_for_can_not_find_opadapter

Merge pull request !1108 from YuJianfeng/master

Merge pull request !1092 from dengwentao/rts_kerenl

Merge pull request !1038 from jinyaohui/clean_context

Merge pull request !1070 from liuxiao/ops-for-VM

Merge pull request !1103 from caifubi/clean-runtime-codex

Merge pull request !1109 from Jamie/fixoneline

Merge pull request !1090 from JichenZhao/layernorm_mean_var_shape

Merge pull request !1086 from SanjayChan/05showcase

Merge pull request !1056 from Xiaoda/memory-estimation-in-inference-phase

Merge pull request !1087 from SanjayChan/03cell

fix error

while do not need ignore vale

Merge pull request !1088 from YuJianfeng/master

Merge pull request !1093 from yihuaijie/master

Merge pull request !683 from xychow/bypass-renorm-and-specialize-hypermap-parameter

Merge pull request !1062 from liuxiao/softplus-softplusgrad