[SR-7600] Re-enabled disabled tests

[gottesmm]

Previous ID	SR-7600
Radar	None
Original Reporter	@gottesmm
Type	Bug

Additional Detail from JIRA

Votes	0
Component/s
Labels	Bug
Assignee	None
Priority	Medium

md5: 70edde113d233bcec1afd29198c00d81

Issue Description:

Just did a quick go through of the tests and found the following disabled tests. We should look into re-enabling them.

IRGen/empty_array.sil
Interpreter/SDK/CoreImage_without_Foundation.swift
SIL/Parser/witness_with_inherited_gp.sil
SourceKit/CursorInfo/cursor_no_cancel.swift
SIL/Serialization/deserialize_appkit.sil
SIL/Serialization/deserialize_foundation.sil
Interpreter/SDK/CoreGraphics_CGFloat.swift
Syntax/round_trip_stdlib.swift
IDE/reconstruct_type_from_mangled_name_invalid.swift
Misc/expression_too_complex_3.swift
SILGen/objc_nonnull_lie_hack.swift
SILOptimizer/dead_code_elimination.sil
Migrator/wrap_optional.swift

[belkadan]

Please file separate bugs for each component, at least, if not each test. No one person's going to resolve this.