[Backtracing][WIP] Add some debug to track down problem in Linux CI.

Author: al45tair

stdlib/public/Backtracing/Backtrace.swift

@@ -547,6 +547,7 @@ public struct Backtrace: CustomStringConvertible, Sendable {
         var endOfText: Address = range.low
 
         if let image = try? Elf32Image(source: subSource) {
+          print("\(path) is an ELF32 image")
           theUUID = image.uuid
 
           for hdr in image.programHeaders {
@@ -556,6 +557,7 @@ public struct Backtrace: CustomStringConvertible, Sendable {
             }
           }
         } else if let image = try? Elf64Image(source: subSource) {
+          print("\(path) is an ELF64 image")
           theUUID = image.uuid
 
           for hdr in image.programHeaders {
@@ -566,6 +568,7 @@ public struct Backtrace: CustomStringConvertible, Sendable {
           }
         } else {
           // Not a valid ELF image
+          print("\(path) is not an ELF image")
           continue
         }
 

stdlib/public/Backtracing/SymbolicatedBacktrace.swift

@@ -479,6 +479,7 @@ public struct SymbolicatedBacktrace: CustomStringConvertible {
            where: { address >= $0.baseAddress
                       && address < $0.endOfText }
          ) {
+
         let relativeAddress = address - FileImageSource.Address(theImages[imageNdx].baseAddress)
         var symbol: Symbol = Symbol(imageIndex: imageNdx,
                                     imageName: theImages[imageNdx].name,