[ExecutionEngine] Fix the call to DWARFContext::create

Without this patch, we pass G.getEndianness() as one of the parameters
to DWARFContext::create.  The problem is that G.getEndianness() is of:

  enum endianness {big, little, native};

whereas DWARFContext::create is expecting "bool isLittleEndian".  That
is, we are relying on an implicit conversion to convert big and little
to false and true, respectively.

When we migrate llvm::support::endianness to std::endian in future, we
can no longer rely on an implicit conversion because std::endian is
declared with "enum class".  Even if we could, the conversion would
not be guaranteed to work because, for example, libcxx defines:

  enum class endian {
    little = 0xDEAD,
    big = 0xFACE,
    :

where big and little are not boolean values.

This patch fixes the problem by properly converting G.getEndianness()
to a boolean value.

Author: kazutakahirata

llvm/lib/ExecutionEngine/Orc/Debugging/DebuggerSupportPlugin.cpp

@@ -158,8 +158,12 @@ class MachODebugObjectSynthesizer : public MachODebugObjectSynthesizerBase {
 
     std::optional<StringRef> FileName;
     if (!DebugLineSectionData.empty()) {
+      assert((G.getEndianness() == support::endianness::big ||
+              G.getEndianness() == support::endianness::little) &&
+             "G.getEndianness() must be either big or little");
       auto DWARFCtx = DWARFContext::create(DebugSectionMap, G.getPointerSize(),
-                                           G.getEndianness());
+                                           G.getEndianness() ==
+                                               support::endianness::little);
       DWARFDataExtractor DebugLineData(
           DebugLineSectionData,
           G.getEndianness() == support::endianness::little, G.getPointerSize());