Fix Odb.RemoveRoutingObstructions failing with non-integer coordinates

[urish]

When specifying non integer coordinates in ROUTING_OBSTRUCTIONS, the Odb.RemoveRoutingObstructions would fail as it would truncate the decimal part before trying to match the coordinate.

For example, the following config would fail on any project (due to 16.5 appearing in the coordinate list):

  "ROUTING_OBSTRUCTIONS": [
    "met1 10 10 20 16.5"
  ],

[donn]

Why are we converting dbus to microns just to convert them back to DBUs? @kareefardi

[kareefardi]

Why are we converting dbus to microns just to convert them back to DBUs? @kareefardi

add_obstructions:

• takes microns
• convert to dbus
• creates an obstruction using dbu

remove_obstructions:

• takes microns
• iterates over existing obstructions (in dbu)
• converts to microns for comparison
• removes if match

There is no redundancy here. The input should be in microns

[donn]

why not convert both to dbus and compare in integer space where things are more reliable?

[donn]

@kareefardi I updated the code to not use floats. Please review.