Fix LLDB data formatter for llvm::Expected<T> with non-reference types (#179294)

This patch fixes LLDB data formatter support for llvm::Expected<T> with
the following changes:

llvm/utils/lldbDataFormatters.py: Fix ExpectedSynthProvider to handle
non-templated storage types (e.g., int, int*). Previously the formatter
only worked with templated storage types like std::reference_wrapper<T>.

cross-project-tests/lit.cfg.py:

Fix get_lldb_version_string() to use locally-built LLDB on non-Darwin
platforms instead of system LLDB
Fix minimum version from "1900" to "19.0.0" (typo in original code)
New test files: Added expected.cpp and expected.test to test the
formatter with Expected<int> and Expected<int*>.

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Co-authored-by: Jeffrey Tan <jeffreytan@fb.com>

0 files changed, 0 insertions, 0 deletions