Eliminate Compiler Warnings

[PhilippvK]

See below.

ninja: Entering directory `build'
[1/2] Building CXX object tools/pattern-gen/CMakeFiles/pattern-gen.dir/LLVMOverride.cpp.o
In file included from /tmp/seal5_llvm_demo/.seal5/deps/cdsl2llvm/llvm/tools/pattern-gen/PatternGen.hpp:2,
                 from /tmp/seal5_llvm_demo/.seal5/deps/cdsl2llvm/llvm/tools/pattern-gen/LLVMOverride.cpp:11:
/tmp/seal5_llvm_demo/.seal5/deps/cdsl2llvm/llvm/tools/pattern-gen/lib/InstrInfo.hpp: In static member function ‘static CDSLInstr::Field CDSLInstr::Field::ConstField(uint32_t, uint8_t, uint8_t)’:
/tmp/seal5_llvm_demo/.seal5/deps/cdsl2llvm/llvm/tools/pattern-gen/lib/InstrInfo.hpp:34: warning: C++ designated initializers only available with ‘-std=c++2a’ or ‘-std=gnu++2a’ [-Wpedantic]
   34 |                 .type = CONST,
      | 
/tmp/seal5_llvm_demo/.seal5/deps/cdsl2llvm/llvm/tools/pattern-gen/lib/InstrInfo.hpp:35: warning: C++ designated initializers only available with ‘-std=c++2a’ or ‘-std=gnu++2a’ [-Wpedantic]
   35 |                 .len = len,
      | 
/tmp/seal5_llvm_demo/.seal5/deps/cdsl2llvm/llvm/tools/pattern-gen/lib/InstrInfo.hpp:36: warning: C++ designated initializers only available with ‘-std=c++2a’ or ‘-std=gnu++2a’ [-Wpedantic]
   36 |                 .dstOffset = offset,
      | 
/tmp/seal5_llvm_demo/.seal5/deps/cdsl2llvm/llvm/tools/pattern-gen/lib/InstrInfo.hpp:37: warning: C++ designated initializers only available with ‘-std=c++2a’ or ‘-std=gnu++2a’ [-Wpedantic]
   37 |                 .srcOffset = 0,
      | 
/tmp/seal5_llvm_demo/.seal5/deps/cdsl2llvm/llvm/tools/pattern-gen/lib/InstrInfo.hpp:38: warning: C++ designated initializers only available with ‘-std=c++2a’ or ‘-std=gnu++2a’ [-Wpedantic]
   38 |                 .value = value
      | 
/tmp/seal5_llvm_demo/.seal5/deps/cdsl2llvm/llvm/tools/pattern-gen/lib/InstrInfo.hpp:39: warning: ISO C++ forbids compound-literals [-Wpedantic]
   39 |             };
      | 
/tmp/seal5_llvm_demo/.seal5/deps/cdsl2llvm/llvm/tools/pattern-gen/lib/InstrInfo.hpp: In static member function ‘static CDSLInstr::Field CDSLInstr::Field::RegImmField(int, uint8_t, uint8_t, uint8_t, bool, uint32_t)’:
/tmp/seal5_llvm_demo/.seal5/deps/cdsl2llvm/llvm/tools/pattern-gen/lib/InstrInfo.hpp:46: warning: C++ designated initializers only available with ‘-std=c++2a’ or ‘-std=gnu++2a’ [-Wpedantic]
   46 |                 .type = static_cast<FieldType>(ID_RD + reg),
      | 
/tmp/seal5_llvm_demo/.seal5/deps/cdsl2llvm/llvm/tools/pattern-gen/lib/InstrInfo.hpp:47: warning: C++ designated initializers only available with ‘-std=c++2a’ or ‘-std=gnu++2a’ [-Wpedantic]
   47 |                 .len = len,
      | 
/tmp/seal5_llvm_demo/.seal5/deps/cdsl2llvm/llvm/tools/pattern-gen/lib/InstrInfo.hpp:48: warning: C++ designated initializers only available with ‘-std=c++2a’ or ‘-std=gnu++2a’ [-Wpedantic]
   48 |                 .dstOffset = dstOffset,
      | 
/tmp/seal5_llvm_demo/.seal5/deps/cdsl2llvm/llvm/tools/pattern-gen/lib/InstrInfo.hpp:49: warning: C++ designated initializers only available with ‘-std=c++2a’ or ‘-std=gnu++2a’ [-Wpedantic]
   49 |                 .srcOffset = srcOffset,
      | 
/tmp/seal5_llvm_demo/.seal5/deps/cdsl2llvm/llvm/tools/pattern-gen/lib/InstrInfo.hpp:50: warning: C++ designated initializers only available with ‘-std=c++2a’ or ‘-std=gnu++2a’ [-Wpedantic]
   50 |                 .value = ((uint32_t)immS << 31) | (immSize & 0x7fffffff)
      | 
/tmp/seal5_llvm_demo/.seal5/deps/cdsl2llvm/llvm/tools/pattern-gen/lib/InstrInfo.hpp:51: warning: ISO C++ forbids compound-literals [-Wpedantic]
   51 |             };
      | 
/tmp/seal5_llvm_demo/.seal5/deps/cdsl2llvm/llvm/tools/pattern-gen/LLVMOverride.cpp: At global scope:
/tmp/seal5_llvm_demo/.seal5/deps/cdsl2llvm/llvm/tools/pattern-gen/LLVMOverride.cpp:76: warning: ‘virtual void RISCVDAGToPatterns::PreprocessISelDAG()’ can be marked override [-Wsuggest-override]
   76 |   void PreprocessISelDAG() {
      | 
[2/2] Linking CXX executable bin/pattern-gen