Add support for only a .eh_frame.

Static executables only have a .eh_frame section and no .eh_frame_hdr
section. Add support for this by rearranging the class hierarchy and
creating a DwarfEhFrameWithHdr class and a DwarfEhFrame class to handle
the different cases.

Add new unit tests for DwarfEhFrame and for the new functionality.

Bug: 68820189

Test: Passes new unit tests, unwinds static executables.
Change-Id: I63d7cb8c52a686e96579a2266e18c0d06bbb6e63
diff --git a/libunwindstack/DwarfDebugFrame.h b/libunwindstack/DwarfDebugFrame.h
index 6a6178e..635cefd 100644
--- a/libunwindstack/DwarfDebugFrame.h
+++ b/libunwindstack/DwarfDebugFrame.h
@@ -28,51 +28,21 @@
 template <typename AddressType>
 class DwarfDebugFrame : public DwarfSectionImpl<AddressType> {
  public:
-  // Add these so that the protected members of DwarfSectionImpl
-  // can be accessed without needing a this->.
-  using DwarfSectionImpl<AddressType>::memory_;
-  using DwarfSectionImpl<AddressType>::fde_count_;
-  using DwarfSectionImpl<AddressType>::last_error_;
-
-  struct FdeInfo {
-    FdeInfo(uint64_t offset, uint64_t start, uint64_t length)
-        : offset(offset), start(start), end(start + length) {}
-
-    uint64_t offset;
-    AddressType start;
-    AddressType end;
-  };
-
-  DwarfDebugFrame(Memory* memory) : DwarfSectionImpl<AddressType>(memory) {}
+  DwarfDebugFrame(Memory* memory) : DwarfSectionImpl<AddressType>(memory) {
+    this->cie32_value_ = static_cast<uint32_t>(-1);
+    this->cie64_value_ = static_cast<uint64_t>(-1);
+  }
   virtual ~DwarfDebugFrame() = default;
 
-  bool Init(uint64_t offset, uint64_t size) override;
+  uint64_t GetCieOffsetFromFde32(uint32_t pointer) override {
+    return this->entries_offset_ + pointer;
+  }
 
-  bool GetFdeOffsetFromPc(uint64_t pc, uint64_t* fde_offset) override;
-
-  const DwarfFde* GetFdeFromIndex(size_t index) override;
-
-  bool IsCie32(uint32_t value32) override { return value32 == static_cast<uint32_t>(-1); }
-
-  bool IsCie64(uint64_t value64) override { return value64 == static_cast<uint64_t>(-1); }
-
-  uint64_t GetCieOffsetFromFde32(uint32_t pointer) override { return offset_ + pointer; }
-
-  uint64_t GetCieOffsetFromFde64(uint64_t pointer) override { return offset_ + pointer; }
+  uint64_t GetCieOffsetFromFde64(uint64_t pointer) override {
+    return this->entries_offset_ + pointer;
+  }
 
   uint64_t AdjustPcFromFde(uint64_t pc) override { return pc; }
-
-  bool GetCieInfo(uint8_t* segment_size, uint8_t* encoding);
-
-  bool AddFdeInfo(uint64_t entry_offset, uint8_t segment_size, uint8_t encoding);
-
-  bool CreateSortedFdeList();
-
- protected:
-  uint64_t offset_;
-  uint64_t end_offset_;
-
-  std::vector<FdeInfo> fdes_;
 };
 
 }  // namespace unwindstack