Merging r308824:

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r308824 | yamaguchi | 2017-07-22 05:35:15 -0700 (Sat, 22 Jul 2017) | 5 lines

[Bash-autocompletion] Fixed typo and add '-' after -Wno

Summary: -Wno-<warning> was autocompleted as -Wno<warning>, so fixed this typo.

Differential Revision: https://reviews.llvm.org/D35762
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llvm-svn: 309130