[WIP][SourceManager] Reorganize methods for line and column

[rintaro]

Reorganize SourceManager methods regarding filename, line and column.
https://lists.swift.org/pipermail/swift-dev/Week-of-Mon-20170313/004232.html
The first commit is strictly NFC.

Presumed locations ( respects #sourceLocation directive)
getBufferIdentifierForLoc(Loc) → getPresumedFilenameForLoc(Loc)
getLineAndColumn(Loc) → getPresumedLineAndColumnForLoc(Loc)

Physical locations (ignores #sourceLocation directive)
getIdentifierForBuffer(BufferID) → ASIS
new getIdentifierForBuffer(Loc)
getLineNumber(Loc) → getLineAndColumnInBuffer(Loc).first
resolveFromLineCol(BufferID, Line, Column) → getOffsetForLineAndColumnInBuffer(BufferID, Line, Column)
getLocForLineCol(BufferID, Line, Column) → getLocForLineAndColumnInBuffer(BufferID, Line, Column)

---

Audit checklist

• AST
  • ASTScope::print
  • ConformanceLookupTable::compareProtocolConformances
  • DeclContext::printContext
  • GenericSignatureBuilder::RequirementSource::print
  • SingleRawComment::SingleRawComment → Use physical line and column, modified
• Basic
  • SourceLoc::printLineAndColumn
  • swift::writeEditsInJson → Use physical filename, asis
• Frontend
  • DiagnosticVerifier::verifyFile
  • SourceManager::GetMessage → Use presumed filename, line and column, asis.
• IDE
  • SerializedDiagnosticConsumer::addLocToRecord
  • CommentToXMLConverter::visitDocComment
  • swift::ide::getLocationInfo
  • swift::ide::reformat (lib/IDE/Formatting.cpp)
• IRGen
  • PrettySourceFileEmission::print
  • IRGenDebugInfo::IRGenDebugInfo
• Index
  • index::indexSourceFile
• Parse
  • Lexer::getLocForStartOfToken → Unused function, removed
  • Parser::parseLineDirective → Use physical line, asis
  • Parser::parseTrailingClosure → Use physical line, asis
  • Parser::parseStmtReturn → Use physical column, modified
• SIL
  • SILLocation::decode
• SILGen
  • SILGenFunction::emitLiteral (#file value) Use presumed filename, asis
  • SILGenFunction::emitPreconditionOptionalHasValue Use presumed filename and line, modified
  • RValueEmitter::visitMagicIdentifierLiteralExpr (#line and #column value) Use presumed line and column, asis
  • CoverageMapping::emitSourceRegions
• Sema
  • NameBinder::addImport
  • FailureDiagnosis::visitApplyExpr → Use physical line, asis
  • swift::performStmtDiagnostics → Use physical line and column, modified
  • swift::performPCMacro
  • swift::performPlaygroundTransform
  • static diagnoseAndMigrateVarParameterToBody → Use physical line, asis
• Serialization
  • GroupNameCollectorFromJson::getGroupNameInternal
• SourceKit
  • EditorDiagConsumer::handleDiagnostic
  • SwiftEditorSyntaxWalker::walkToNodePre
  • SwiftEditorDocument::replaceText
• swift-ide-test
  • AnnotationPrinter::printLoc
  • ASTTypePrinter::walkToExprPre
  • ASTCommentPrinter::walkToDeclPre
  • USRPrinter::printLoc

[CodaFi]

@rintaro Can we still take this?

[rintaro]

@owenv is taking over this effort in #31943 . Closing.