[TableGen] Remove unused includes (NFC) (#141356)

These are identified by misc-include-cleaner.  I've filtered out those
that break builds.  Also, I'm staying away from llvm-config.h,
config.h, and Compiler.h, which likely cause platform- or
compiler-specific build failures.

Author: kazutakahirata

llvm/utils/TableGen/Basic/ARMTargetDefEmitter.cpp

@@ -19,7 +19,6 @@
 #include "llvm/TableGen/Error.h"
 #include "llvm/TableGen/Record.h"
 #include "llvm/TableGen/TableGenBackend.h"
-#include <cstdint>
 #include <set>
 #include <string>
 

llvm/utils/TableGen/Common/CodeGenTarget.cpp

@@ -23,7 +23,6 @@
 #include "llvm/Support/ErrorHandling.h"
 #include "llvm/TableGen/Error.h"
 #include "llvm/TableGen/Record.h"
-#include <algorithm>
 #include <iterator>
 #include <tuple>
 using namespace llvm;

llvm/utils/TableGen/DecoderEmitter.cpp

@@ -32,7 +32,6 @@
 #include "llvm/Support/CommandLine.h"
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/ErrorHandling.h"
-#include "llvm/Support/FormatVariadic.h"
 #include "llvm/Support/FormattedStream.h"
 #include "llvm/Support/LEB128.h"
 #include "llvm/Support/MathExtras.h"

llvm/utils/TableGen/SearchableTableEmitter.cpp

@@ -22,7 +22,6 @@
 #include "llvm/TableGen/Error.h"
 #include "llvm/TableGen/Record.h"
 #include "llvm/TableGen/TableGenBackend.h"
-#include <algorithm>
 #include <set>
 #include <string>
 #include <vector>

llvm/utils/TableGen/SubtargetEmitter.cpp

@@ -21,7 +21,6 @@
 #include "llvm/ADT/StringExtras.h"
 #include "llvm/ADT/StringMap.h"
 #include "llvm/ADT/StringRef.h"
-#include "llvm/ADT/StringSwitch.h"
 #include "llvm/MC/MCInstrItineraries.h"
 #include "llvm/MC/MCSchedule.h"
 #include "llvm/Support/Debug.h"