[llvm] [llvm-mc] Don't print initial .text for disassembler (PR #120185)

[Fangrui Song via llvm-commits]

================
@@ -169,7 +169,7 @@ int Disassembler::disassemble(const Target &T, const std::string &Triple,
   }
 
   // Set up initial section manually here
-  Streamer.initSections(false, STI);
+  Streamer.switchSectionNoPrint(Ctx.getObjectFileInfo()->getTextSection());
----------------
MaskRay wrote:

I investigated further. This call is only needed by AIX XCOFF https://reviews.llvm.org/D95518 .

```
echo 7c4303a6 | rrllvm-mc --cdis --hex --triple=powerpc-aix-ibm-xcoff
```

I deleted this statement and adjusted MCAsmStreamer.

https://github.com/llvm/llvm-project/pull/120185