[WebAssembly] Remove duplicate function. NFC.

[ruiu]

LGTM

test/wasm/lto/signature-mismatch.ll

 ; f is defined to take no argument in archive.ll which is compiled to bitcode
 declare void @f(i32);
 
 define void @_start() {
   call void @f(i32 0)
   ret void
 }
 
-; CHECK: >>> defined as (I32) -> void in {{.*}}signature-mismatch.ll.tmp1.o
+; CHECK: >>> defined as (i32) -> void in {{.*}}signature-mismatch.ll.tmp1.o
 ; CHECK: >>> defined as () -> void in lto.tmp

test/wasm/signature-mismatch-weak.ll

 ; RUN: llc -filetype=obj %p/Inputs/weak-symbol1.ll -o %t.weak.o
 ; RUN: llc -filetype=obj %p/Inputs/strong-symbol.ll -o %t.strong.o
 ; RUN: llc -filetype=obj %s -o %t.o
 ; RUN: wasm-ld -o %t.wasm %t.o %t.strong.o %t.weak.o 2>&1 | FileCheck %s
 
 target triple = "wasm32-unknown-unknown"
 
 declare i32 @weakFn() local_unnamed_addr
 
 define void @_start() local_unnamed_addr {
 entry:
   %call = call i32 @weakFn()
   ret void
 }
 
 ; CHECK: warning: function signature mismatch: weakFn
-; CHECK-NEXT: >>> defined as () -> I32 in {{.*}}signature-mismatch-weak.ll.tmp.o
-; CHECK-NEXT: >>> defined as () -> I64 in {{.*}}signature-mismatch-weak.ll.tmp.strong.o
+; CHECK-NEXT: >>> defined as () -> i32 in {{.*}}signature-mismatch-weak.ll.tmp.o
+; CHECK-NEXT: >>> defined as () -> i64 in {{.*}}signature-mismatch-weak.ll.tmp.strong.o

test/wasm/signature-mismatch.ll

 entry:
   %call = tail call i32 @ret32(i32 1, i64 2, i32 3) #2
   ret void
 }
 
 declare i32 @ret32(i32, i64, i32) local_unnamed_addr #1
 
 ; CHECK: error: function signature mismatch: ret32
-; CHECK-NEXT: >>> defined as (I32, I64, I32) -> I32 in {{.*}}.main.o
-; CHECK-NEXT: >>> defined as (F32) -> I32 in {{.*}}.ret32.o
+; CHECK-NEXT: >>> defined as (i32, i64, i32) -> i32 in {{.*}}.main.o
+; CHECK-NEXT: >>> defined as (f32) -> i32 in {{.*}}.ret32.o
 
 ; REVERSE: error: function signature mismatch: ret32
-; REVERSE-NEXT: >>> defined as (F32) -> I32 in {{.*}}.ret32.o
-; REVERSE-NEXT: >>> defined as (I32, I64, I32) -> I32 in {{.*}}.main.o
+; REVERSE-NEXT: >>> defined as (f32) -> i32 in {{.*}}.ret32.o
+; REVERSE-NEXT: >>> defined as (i32, i64, i32) -> i32 in {{.*}}.main.o

wasm/WriterUtils.cpp

 #include "llvm/Support/LEB128.h"
 
 #define DEBUG_TYPE "lld"
 
 using namespace llvm;
 using namespace llvm::wasm;
 using namespace lld::wasm;
 
-static const char *valueTypeToString(ValType Type) {
-  switch (Type) {
-  case wasm::ValType::I32:
-    return "i32";
-  case wasm::ValType::I64:
-    return "i64";
-  case wasm::ValType::F32:
-    return "f32";
-  case wasm::ValType::F64:
-    return "f64";
-  default:
-    llvm_unreachable("invalid value type");
-  }
-}
-
 namespace lld {
 
 void wasm::debugWrite(uint64_t Offset, const Twine &Msg) {
   LLVM_DEBUG(dbgs() << format("  | %08lld: ", Offset) << Msg << "\n");
 }
 
 void wasm::writeUleb128(raw_ostream &OS, uint32_t Number, const Twine &Msg) {
   debugWrite(OS.tell(), Msg + "[" + utohexstr(Number) + "]");

 
 void wasm::writeU32(raw_ostream &OS, uint32_t Number, const Twine &Msg) {
   debugWrite(OS.tell(), Msg + "[0x" + utohexstr(Number) + "]");
   support::endian::write(OS, Number, support::little);
 }
 
 void wasm::writeValueType(raw_ostream &OS, ValType Type, const Twine &Msg) {
   writeU8(OS, static_cast<uint8_t>(Type),
-          Msg + "[type: " + valueTypeToString(Type) + "]");
+          Msg + "[type: " + toString(Type) + "]");
 }
 
 void wasm::writeSig(raw_ostream &OS, const WasmSignature &Sig) {
   writeU8(OS, WASM_TYPE_FUNC, "signature type");
   writeUleb128(OS, Sig.Params.size(), "param Count");
   for (ValType ParamType : Sig.Params) {
     writeValueType(OS, ParamType, "param type");
   }
default:
     fatal("unsupported export type: " + Twine(Export.Kind));
   }
 }
 } // namespace lld
 
 std::string lld::toString(ValType Type) {
   switch (Type) {
   case ValType::I32:
-    return "I32";
+    return "i32";
   case ValType::I64:
-    return "I64";
+    return "i64";
   case ValType::F32:
-    return "F32";
+    return "f32";
   case ValType::F64:
-    return "F64";
+    return "f64";
   case ValType::V128:
-    return "V128";
+    return "v128";
   case ValType::EXCEPT_REF:
     return "except_ref";
   }
   llvm_unreachable("Invalid wasm::ValType");
 }
 
 std::string lld::toString(const WasmSignature &Sig) {
   SmallString<128> S("(");