Add shared separate data section for compact dex

Added a shared dex data buffer for compact dex files, this buffer
is referenced by all compact dex files in a vdex file. Repurposed
the existing data_off / data_size fields in the header.

After the shared buffer is filled up, it is placed after the dex
files in the oat writer and the dex file headers are fixed up to have
the correct offsets / sizes to the shared buffer.

Motivation:
Make it easy to deduplicate data across dexes.

Bug: 63756964
Test: test-art-host
Change-Id: I17855a0c78b20be3d323d12dedb9c695962be3ed
diff --git a/runtime/type_lookup_table.h b/runtime/type_lookup_table.h
index 6a6f47f..50c93ad 100644
--- a/runtime/type_lookup_table.h
+++ b/runtime/type_lookup_table.h
@@ -43,7 +43,7 @@
 
   // Method search class_def_idx by class descriptor and it's hash.
   // If no data found then the method returns dex::kDexNoIndex.
-  ALWAYS_INLINE uint32_t Lookup(const char* str, uint32_t hash) const {
+  uint32_t Lookup(const char* str, uint32_t hash) const {
     uint32_t pos = hash & GetSizeMask();
     // Thanks to special insertion algorithm, the element at position pos can be empty or start of
     // bucket.
@@ -127,8 +127,8 @@
                   uint32_t num_class_defs);
 
   bool IsStringsEquals(const char* str, uint32_t str_offset) const {
-    const uint8_t* ptr = dex_file_begin_ + str_offset;
-    CHECK(dex_file_begin_ != nullptr);
+    const uint8_t* ptr = dex_data_begin_ + str_offset;
+    CHECK(dex_data_begin_ != nullptr);
     // Skip string length.
     DecodeUnsignedLeb128(&ptr);
     return CompareModifiedUtf8ToModifiedUtf8AsUtf16CodePointValues(
@@ -160,7 +160,7 @@
   // Find the last entry in a chain.
   uint32_t FindLastEntryInBucket(uint32_t cur_pos) const;
 
-  const uint8_t* dex_file_begin_;
+  const uint8_t* dex_data_begin_;
   const uint32_t raw_data_length_;
   const uint32_t mask_;
   std::unique_ptr<Entry[]> entries_;