Fix off by 4 error handling eh_frame hdr.

- Add a new tool that can dump the register information given a pc.
- Add a new offline unwinder test that fails without this change.
- Update unit tests.
- Refactor offline unwind tests to make it easier to add tests.

Bug: 73048324

Test: Passes new unit tests.
Test: Passes libbacktrace unit tests.
Test: Ran debuggerd -b on random processes.
Change-Id: If6c70a044299505c2274ae6888b35bf9ac34b74b
diff --git a/libunwindstack/tests/DwarfEhFrameWithHdrTest.cpp b/libunwindstack/tests/DwarfEhFrameWithHdrTest.cpp
index a2ae5eb..4240419 100644
--- a/libunwindstack/tests/DwarfEhFrameWithHdrTest.cpp
+++ b/libunwindstack/tests/DwarfEhFrameWithHdrTest.cpp
@@ -134,7 +134,7 @@
 
   auto info = this->eh_frame_->GetFdeInfoFromIndex(2);
   ASSERT_TRUE(info != nullptr);
-  EXPECT_EQ(0x1384U, info->pc);
+  EXPECT_EQ(0x1380U, info->pc);
   EXPECT_EQ(0x1540U, info->offset);
 }
 
@@ -149,7 +149,7 @@
 
   auto info = this->eh_frame_->GetFdeInfoFromIndex(2);
   ASSERT_TRUE(info != nullptr);
-  EXPECT_EQ(0x3344U, info->pc);
+  EXPECT_EQ(0x3340U, info->pc);
   EXPECT_EQ(0x3500U, info->offset);
 }
 
@@ -163,7 +163,7 @@
 
   auto info = this->eh_frame_->GetFdeInfoFromIndex(2);
   ASSERT_TRUE(info != nullptr);
-  EXPECT_EQ(0x344U, info->pc);
+  EXPECT_EQ(0x340U, info->pc);
   EXPECT_EQ(0x500U, info->offset);
 
   // Clear the memory so that this will fail if it doesn't read cached data.
@@ -171,7 +171,7 @@
 
   info = this->eh_frame_->GetFdeInfoFromIndex(2);
   ASSERT_TRUE(info != nullptr);
-  EXPECT_EQ(0x344U, info->pc);
+  EXPECT_EQ(0x340U, info->pc);
   EXPECT_EQ(0x500U, info->offset);
 }