[yaml2obj] - Change how p_offset is calculated when creating segments. NFCI.

This depends on D78361 and simplifies the computation of the `p_offset`.

Differential revision: https://reviews.llvm.org/D78363

Author: Georgii Rymar

llvm/lib/ObjectYAML/ELFEmitter.cpp

@@ -759,18 +759,12 @@ void ELFState<ELFT>::setProgramHeaderLayout(std::vector<Elf_Phdr> &PHeaders,
       reportError("sections in the program header with index " +
                   Twine(PhdrIdx) + " are not sorted by their file offset");
 
-    if (YamlPhdr.Offset) {
+    if (YamlPhdr.Offset)
       PHeader.p_offset = *YamlPhdr.Offset;
-    } else {
-      if (YamlPhdr.Sections.size())
-        PHeader.p_offset = UINT32_MAX;
-      else
-        PHeader.p_offset = 0;
-
-      // Find the minimum offset for the program header.
-      for (const Fragment &F : Fragments)
-        PHeader.p_offset = std::min((uint64_t)PHeader.p_offset, F.Offset);
-    }
+    else if (!Fragments.empty())
+      PHeader.p_offset = Fragments.front().Offset;
+    else
+      PHeader.p_offset = 0;
 
     // Find the maximum offset of the end of a section in order to set p_filesz
     // and p_memsz. When setting p_filesz, trailing SHT_NOBITS sections are not