[MC][DecoderEmitter] Fix build warning: explicit specialization cannot have a storage class (#156375)

Move `InsnBitWidth` template into anonymous namespace in the generated
code and move template specialization of `InsnBitWidth` to anonymous
namespace as well, and drop `static` for them. This makes `InsnBitWidth`
completely private to each target and fixes the "explicit specialization
cannot have a storage class" warning as well as any potential linker
errors if `InsnBitWidth` is kept in the `llvm::MCD` namespace.

1 files changed, 5 insertions, 3 deletions

diff --git a/llvm/lib/Target/RISCV/Disassembler/RISCVDisassembler.cpp b/llvm/lib/Target/RISCV/Disassembler/RISCVDisassembler.cpp
index 987d6c7..b1b7ea5 100644
--- a/llvm/lib/Target/RISCV/Disassembler/RISCVDisassembler.cpp
+++ b/llvm/lib/Target/RISCV/Disassembler/RISCVDisassembler.cpp
@@ -701,11 +701,13 @@ static constexpr DecoderListEntry DecoderList32[]{
     {DecoderTableZdinxRV32Only32, {}, "RV32-only Zdinx (Double in Integer)"},
 };
 
+namespace {
 // Define bitwidths for various types used to instantiate the decoder.
-template <> inline constexpr uint32_t llvm::MCD::InsnBitWidth<uint16_t> = 16;
-template <> inline constexpr uint32_t llvm::MCD::InsnBitWidth<uint32_t> = 32;
+template <> constexpr uint32_t InsnBitWidth<uint16_t> = 16;
+template <> constexpr uint32_t InsnBitWidth<uint32_t> = 32;
 // Use uint64_t to represent 48 bit instructions.
-template <> inline constexpr uint32_t llvm::MCD::InsnBitWidth<uint64_t> = 48;
+template <> constexpr uint32_t InsnBitWidth<uint64_t> = 48;
+} // namespace
 
 DecodeStatus RISCVDisassembler::getInstruction32(MCInst &MI, uint64_t &Size,
                                                  ArrayRef<uint8_t> Bytes,