[llvm] [SystemZ][z/OS] TXT records in the GOFF reader (PR #87648)

[Martin Storsjö via llvm-commits]

================
@@ -502,3 +502,100 @@ TEST(GOFFObjectFileTest, InvalidERSymbolType) {
         FailedWithMessage("ESD record 1 has unknown Executable type 0x03"));
   }
 }
+
+TEST(GOFFObjectFileTest, TXTConstruct) {
+  char GOFFData[GOFF::RecordLength * 6] = {};
+
+  // HDR record.
+  GOFFData[0] = 0x03;
+  GOFFData[1] = 0xF0;
----------------
mstorsjo wrote:

This causes lots of warnings when compiled with GCC, like these:
```
../unittests/Object/GOFFObjectFileTest.cpp:511:17: warning: overflow in conversion from ‘int’ to ‘char’ changes value from ‘240’ to ‘'\37777777760'’ [-Woverflow]
  511 |   GOFFData[1] = 0xF0;
      |                 ^~~~
```

https://github.com/llvm/llvm-project/pull/87648