An empty string literal in an asm label does not make a whole lot of sense. GCC
does not diagnose such a construct, but it also generates code that cannot be
assembled by gas should two symbols have an empty asm label within the same TU.
This does not affect an asm statement with an empty string literal, which is
still a useful construct.
Without this fix, the tests introduced here produce the following
assert fail:
```
clang: /home/jdenny/llvm/clang/include/clang/Basic/AttributeCommonInfo.h:163: unsigned int clang::AttributeCommonInfo::getAttributeSpellingListIndex() const: Assertion `(isAttributeSpellingListCalculated() || AttrName) && "Spelling cannot be found"' failed.
```
The bug was introduced by D67368, which caused `AsmLabelAttr`'s
spelling index to be set to `SpellingNotCalculated`.
Reviewed By: aaron.ballman
Differential Revision: https://reviews.llvm.org/D70349
This moves everything primarily testing the functionality of -ast-dump and -ast-print into their own directory, rather than leaving the tests spread around the testing directory.
llvm-svn: 348017
Aaron Ballman