Merging r368478:

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r368478 | void | 2019-08-09 22:18:30 +0200 (Fri, 09 Aug 2019) | 16 lines

[CodeGen] Require a name for a block addr target

Summary:
A block address may be used in inline assembly. In which case it
requires a name so that the asm parser has something to parse. Creating
a name for every block address is a large hammer, but is necessary
because at the point when a temp symbol is created we don't necessarily
know if it's used in inline asm. This ensures that it exists regardless.

Reviewers: nickdesaulniers, craig.topper

Subscribers: nathanchance, javed.absar, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D65352
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llvm-svn: 368678