Refactoring functions related to processImport
Refactoring preProcessFile to use new scanner
Move switchToForwardSlashes from pathUtils to utilities
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Refactoring getFileReferenceFromReferencePath for both parser and language service
Add unittests for preProcessFile
Fix indentation
Fix indentation and space
Merge branch 'refactorRefFilesPath' of https://github.com/Microsoft/TypeScript into refactorRefFilesPath
initial implementation of constant folding
handle non-qualified names, add 'propagateEnumConstants' command line option
added folding for references to enum members in enum member initializers, added tests
addressed CR feedback, added support for indexed access
move code around to consolidate checks in one place
dropped redundand type assertion, added mising check
Fix getTokenPos for scanning import statement
Remove diagnostic from pre-processing of files
Add tests case for invalid syntax in import statement and triple slash reference
merge with master
'const enum' iteration 0. TODO: allow and track const enums in imports, add more tests