Tests Map class.

Bug 74084
Dumping maps:
  First map:
    key1 : undefined
    key2 : undefined
  Second map:
    key1 : undefined
    key2 : undefined

Dumping maps:
  First map:
    key1 : 2
    key2 : undefined
  Second map:
    key1 : undefined
    key2 : undefined

Dumping maps:
  First map:
    key1 : 1
    key2 : undefined
  Second map:
    key1 : undefined
    key2 : undefined

Dumping maps:
  First map:
    key1 : 1
    key2 : undefined
  Second map:
    key1 : 1
    key2 : undefined

Dumping maps:
  First map:
    key1 : 1
    key2 : undefined
  Second map:
    key1 : 2
    key2 : undefined

Dumping maps:
  First map:
    key1 : 1
    key2 : 2
  Second map:
    key1 : 2
    key2 : undefined

Dumping maps:
  First map:
    key1 : 1
    key2 : 2
  Second map:
    key1 : 2
    key2 : 1

Dumping maps:
  First map:
    key1 : 1
    key2 : undefined
  Second map:
    key1 : 2
    key2 : 1

Dumping maps:
  First map:
    key1 : 1
    key2 : undefined
  Second map:
    key1 : 2
    key2 : undefined

Dumping maps:
  First map:
    key1 : 1
    key2 : undefined
  Second map:
    key1 : 2
    key2 : undefined

Dumping maps:
  First map:
    key1 : undefined
    key2 : undefined
  Second map:
    key1 : 2
    key2 : undefined

Dumping maps:
  First map:
    key1 : undefined
    key2 : undefined
  Second map:
    key1 : undefined
    key2 : undefined