[NFC][ScopBuilder] Move buildDomains and its callees to ScopBuilder.

Scope of changes:

1) Moved buildDomains function to ScopBuilder class.
2) Moved buildDomainsWithBranchConstraints function to ScopBuilder class.
3) Moved propagateDomainConstraints to ScopBuilder class.
4) Moved propagateDomainConstraintsToRegionExit to ScopBuilder class.
5) Moved propagateInvalidStmtDomains to ScopBuilder class.
6) Moved getPredecessorDomainConstraints function to ScopBuilder class.
7) Moved addLoopBoundsToHeaderDomain function to ScopBuilder class.
8) Moved getPwAff function to ScopBuilder class.
9) Moved buildConditionSets functions to ScopBuilder class.
10) Added updateMaxLoopDepth, notifyErrorBlock, getOrInitEmptyDomain, isDomainDefined, setDomain functions to Scop class. They are used by ScopBuilder.
11) Moved helper functions: getRegionNodeBasicBlock, getRegionNodeSuccessor, containsErrorBlock, createNextIterationMap, collectBoundedParts, partitionSetParts, buildConditionSet to ScopBuilder.cpp file.

Differential Revision: https://reviews.llvm.org/D65729

llvm-svn: 368100