[DynInst_API:] COMMIT (2/3): Utility Support for Stack Modifications

[Emily Gember-Jacobson <jacobson@xxxxxxxxxxx>]

This series of commits enables internal functionality required to support stack modifications.

Commit ab227591ae33e739e0f6a472225ec64f685a2cd1

 ÂÂAdd reverse iterators and an updateValue function to IntervalTree.

Commit 88c78a6bfcdc09202e1ca049307ff57f7ca518cb

  Add support for the x86::gs and x86_64::fs registers

Commit bdcf44378282b0fee97b90c5e41a7191a6be2edb

 ÂÂAdd emit functions to handle various operations with segment registers

Commit 4d49c87dddd5568017c5d5e8467e1a8d6e02d458

 ÂÂMove emitLEA into the Emitter class

Commit 9063e1517dfef0c9c0884c174b3b48c035342ef3

 ÂÂAdd flag to codeGen class to generate instrumentation code without baseTramp saves and restores.

Commit f72fec5fd69588188d9df85ef9ca311ca7e66123

 ÂÂRecord the frameOffset as an absolute offset in VariableLocation (in addition to the existing relative offset)

Commit e016850044092b4b2479bd4602e6eb0d0a0bc5f4

 ÂÂAdd several fortran functions to list of known non-returning functions