.swiftinterface files into the dSYM bundle. These typically come only
from the SDK (since textual interfaces require library evolution) and
thus are a waste of space to copy into the bundle.

The information about this is being parsed out of the control block,
which means duplicating 5 constants from the Swift frontend. If a file
cannot be parsed, dsymutil errs on the side of copying the file
anyway.

rdar://138186524

Relanding with additional linker dependency and moving the test into
the right target subdirectory.

This reverts commit 39ace8a63012af7d6ad7bf065c233fd3d5df44a3.

while investigating Linux bot failures.

.swiftinterface files into the dSYM bundle. These typically come only
from the SDK (since textual interfaces require library evolution) and
thus are a waste of space to copy into the bundle.

The information about this is being parsed out of the control block,
which means duplicating 5 constants from the Swift frontend. If a file
cannot be parsed, dsymutil errs on the side of copying the file anyway.

rdar://138186524

I (re)discovered that dsymutil was instantiating two BinaryHolders: one
for parsing the debug map and one for linking. That really defeats the
purpose of the BinaryHolder as it serves as a cache. Fix the issue and
remove an old FIXME.

This patch renames {starts,ends}with to {starts,ends}_with for
consistency with std::{string,string_view}::{starts,ends}_with in
C++20.  Since there are only a handful of occurrences, this patch
skips the deprecation phase and simply renames them.

Reland https://reviews.llvm.org/D158124
Fixed `-fpermissive` error reported by gcc only.

This reverts commit 122c89b271af30b86536cad7bac64ea9c56615ed. Change does not build, with errors such as:

In file included from ../llvm-project/llvm/tools/dsymutil/DebugMap.h:24,
                 from ../llvm-project/llvm/tools/dsymutil/DwarfLinkerForBinary.h:13,
                 from ../llvm-project/llvm/tools/dsymutil/DwarfLinkerForBinary.cpp:9:
../llvm-project/llvm/tools/dsymutil/RelocationMap.h:60:17: error: declaration of ‘llvm::dsymutil::SymbolMapping llvm::dsymutil::ValidReloc::SymbolMapping’ changes meaning of ‘SymbolMapping’ [-fpermissive]
   60 |   SymbolMapping SymbolMapping;
      |                 ^~~~~~~~~~~~~
../llvm-project/llvm/tools/dsymutil/RelocationMap.h:36:8: note: ‘SymbolMapping’ declared here as ‘struct llvm::dsymutil::SymbolMapping’
   36 | struct SymbolMapping {
      |        ^~~~~~~~~~~~~
In file included from ../llvm-project/llvm/tools/dsymutil/DwarfLinkerForBinary.h:13,
                 from ../llvm-project/llvm/tools/dsymutil/DwarfLinkerForBinary.cpp:9:
../llvm-project/llvm/tools/dsymutil/DebugMap.h:198:32: error: declaration of ‘std::optional<llvm::dsymutil::RelocationMap> llvm::dsymutil::DebugMapObject::RelocationMap’ changes meaning of ‘RelocationMap’ [-fpermissive]
  198 |   std::optional<RelocationMap> RelocationMap;
      |                                ^~~~~~~~~~~~~
In file included from ../llvm-project/llvm/tools/dsymutil/DebugMap.h:24,
                 from ../llvm-project/llvm/tools/dsymutil/DwarfLinkerForBinary.h:13,
                 from ../llvm-project/llvm/tools/dsymutil/DwarfLinkerForBinary.cpp:9:
../llvm-project/llvm/tools/dsymutil/RelocationMap.h:76:7: note: ‘RelocationMap’ declared here as ‘class llvm::dsymutil::RelocationMap’
   76 | class RelocationMap {
      |       ^~~~~~~~~~~~~

This adds support in dsymutil for mergeable libraries [1].

dsymutil reads a new stab emitted by ld, allowing it to operate on
dynamic libraries instead of object files. It also now loads the DWARF
files associated to the libraries, and build the debug map for each
binary from the list of symbols exported by the library. For each Debug
Map Object, there is a new associated Relocation Map which is serialized
from the information retrieved in the original debug_info (or
debug_addr) section of the .o file.

The final DWARF file has multiple compile units, so the offsets
information of the relocations are adjusted relatively to the compile
unit they will end up belonging to, inside the final linked DWARF file.

[1] https://developer.apple.com/documentation/xcode/configuring-your-project-to-use-mergeable-libraries

Differential revision: https://reviews.llvm.org/D158124

Identified with misc-include-cleaner.

Similar to the llvm::sort call in DebugMapObject::print.