swift234

Revert "Runtime: Enable reflection for multi-payload enums with non-trivial layout"

This reverts commit r30215.

Fixes a bunch of problems on the ASAN bot.

Before:
    Swift :: 1_stdlib/ErrorType.swift
    Swift :: 1_stdlib/Runtime.swift
    Swift :: Constraints/bridging.swift
    Swift :: Constraints/diagnostics.swift
    Swift :: Constraints/lvalues.swift
    Swift :: DebugInfo/variables-repl.swift
    Swift :: Interpreter/enum_runtime_alignment.swift
    Swift :: Interpreter/nil_error_value.swift
    Swift :: Interpreter/return_from_main.swift
    Swift :: Misc/misc_diagnostics.swift
    Swift :: Prototypes/Result.swift
    Swift :: expr/expressions.swift
    Swift-Unit :: runtime/SwiftRuntimeTests/MetadataTest.installCommonValueWitnesses_pod_indirect

After:
    Swift :: Constraints/bridging.swift
    Swift :: Constraints/diagnostics.swift
    Swift :: Constraints/lvalues.swift
    Swift :: Misc/misc_diagnostics.swift
    Swift :: expr/expressions.swift
    Swift-Unit :: runtime/SwiftRuntimeTests/MetadataTest.installCommonValueWitnesses_pod_indirect

Swift SVN r30396