[DSC] Simplify file mapping to fix intermittent unrelocated pointers

The `FileAccessorCache`'s LRU eviction could discard a file's mapped
data after slide info had already been applied to it. Future accesses to
the file produced a fresh mapping, but failed to reapply the slide info.
This could result in pointers not correctly being slid, such as in
https://github.com/Vector35/binaryninja-api/issues/7689.

The LRU cache existed to stay within OS file descriptor limits, since
the old `MappedFile` held its fd open for the lifetime of the mapping.
There's no real reason for it to hold the file descriptor open like
this. Closing it after `mmap` is sufficient to avoid the file descriptor
limits.

`MappedFileRegion` replaces the combination of `FileAccessorCache`,
`WeakFileAccessor`, and `MappedFileAccessor`. It closes the fd
immediately after mmap, so all files can stay mapped without consuming
descriptors, making the cache unnecessary.

`MappedFileRegion` is owned directly by the `CacheEntry` for its full
lifetime. Slide info is applied exactly once to each `MappedFileRegion`.

1 files changed, 1 insertions, 2 deletions

diff --git a/view/sharedcache/core/SharedCacheBuilder.cpp b/view/sharedcache/core/SharedCacheBuilder.cpp
index 15b4b7ac..639b5bc4 100644
--- a/view/sharedcache/core/SharedCacheBuilder.cpp
+++ b/view/sharedcache/core/SharedCacheBuilder.cpp
@@ -43,8 +43,7 @@ bool SharedCacheBuilder::AddFile(
 
 	try
 	{
-		auto entry = CacheEntry::FromFile(filePath, fileName, cacheType);
-		m_cache.AddEntry(std::move(entry));
+		m_cache.AddEntry(CacheEntry::FromFile(filePath, fileName, cacheType));
 	}
 	catch (const std::exception& e)
 	{