[llvm] [AArch64] Generalize costing for FP16 instructions (PR #150033)

[LLVM Continuous Integration via llvm-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `clang-x86_64-debian-fast` running on `gribozavr4` while building `llvm` at step 5 "build-unified-tree".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/56/builds/32886

<details>
<summary>Here is the relevant piece of the build log for the reference</summary>

```
Step 5 (build-unified-tree) failure: build (failure)
...
20.972 [487/16/5836] Running utility command for ocaml_llvm_SPIRV
20.973 [487/15/5837] Building OCaml documentation for llvm_Hexagon
20.975 [486/15/5838] Building OCaml documentation for llvm_RISCV
20.979 [485/15/5839] Running utility command for ocaml_llvm_ARM
20.982 [485/14/5840] Running utility command for ocaml_llvm_Mips
20.985 [485/13/5841] Running utility command for ocaml_llvm_Hexagon
20.986 [485/12/5842] Building OCaml library llvm_executionengine
20.987 [484/12/5843] Building OCaml documentation for llvm_X86
20.987 [483/12/5844] Running utility command for ocaml_llvm_RISCV
20.993 [483/11/5845] Building CXX object lib/Target/AArch64/CMakeFiles/LLVMAArch64CodeGen.dir/AArch64TargetTransformInfo.cpp.o
FAILED: lib/Target/AArch64/CMakeFiles/LLVMAArch64CodeGen.dir/AArch64TargetTransformInfo.cpp.o 
CCACHE_CPP2=yes CCACHE_HASHDIR=yes CCACHE_SLOPPINESS=pch_defines,time_macros /usr/bin/ccache /usr/bin/clang++ -DEXPERIMENTAL_KEY_INSTRUCTIONS -DGTEST_HAS_RTTI=0 -D_DEBUG -D_GLIBCXX_ASSERTIONS -D_GNU_SOURCE -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS -I/b/1/clang-x86_64-debian-fast/llvm.obj/lib/Target/AArch64 -I/b/1/clang-x86_64-debian-fast/llvm.src/llvm/lib/Target/AArch64 -I/b/1/clang-x86_64-debian-fast/llvm.obj/include -I/b/1/clang-x86_64-debian-fast/llvm.src/llvm/include -std=c++11 -Wdocumentation -Wno-documentation-deprecated-sync -fPIC -fvisibility-inlines-hidden -Werror=date-time -Werror=unguarded-availability-new -Wall -Wextra -Wno-unused-parameter -Wwrite-strings -Wcast-qual -Wmissing-field-initializers -pedantic -Wno-long-long -Wc++98-compat-extra-semi -Wimplicit-fallthrough -Wcovered-switch-default -Wno-noexcept-type -Wnon-virtual-dtor -Wdelete-non-virtual-dtor -Wsuggest-override -Wstring-conversion -Wmisleading-indentation -Wctad-maybe-unsupported -fdiagnostics-color -ffunction-sections -fdata-sections -O3 -DNDEBUG -fvisibility=hidden  -fno-exceptions -funwind-tables -fno-rtti -UNDEBUG -std=c++17 -MD -MT lib/Target/AArch64/CMakeFiles/LLVMAArch64CodeGen.dir/AArch64TargetTransformInfo.cpp.o -MF lib/Target/AArch64/CMakeFiles/LLVMAArch64CodeGen.dir/AArch64TargetTransformInfo.cpp.o.d -o lib/Target/AArch64/CMakeFiles/LLVMAArch64CodeGen.dir/AArch64TargetTransformInfo.cpp.o -c /b/1/clang-x86_64-debian-fast/llvm.src/llvm/lib/Target/AArch64/AArch64TargetTransformInfo.cpp
In file included from /b/1/clang-x86_64-debian-fast/llvm.src/llvm/lib/Target/AArch64/AArch64TargetTransformInfo.cpp:9:
In file included from /b/1/clang-x86_64-debian-fast/llvm.src/llvm/lib/Target/AArch64/AArch64TargetTransformInfo.h:20:
In file included from /b/1/clang-x86_64-debian-fast/llvm.src/llvm/lib/Target/AArch64/AArch64Subtarget.h:17:
In file included from /b/1/clang-x86_64-debian-fast/llvm.src/llvm/lib/Target/AArch64/AArch64ISelLowering.h:19:
In file included from /b/1/clang-x86_64-debian-fast/llvm.src/llvm/include/llvm/CodeGen/SelectionDAG.h:31:
/b/1/clang-x86_64-debian-fast/llvm.src/llvm/include/llvm/CodeGen/SelectionDAGNodes.h:2291:10: warning: HTML start tag prematurely ended, expected attribute name or '>' [-Wdocumentation]
  /// "<a, a+n, a+2n, a+3n, ...>" where a is integer and n is a non-zero integer,
         ^
/b/1/clang-x86_64-debian-fast/llvm.src/llvm/include/llvm/CodeGen/SelectionDAGNodes.h:2292:20: warning: HTML start tag prematurely ended, expected attribute name or '>' [-Wdocumentation]
  /// the value "<a,n>" is returned.
                   ^
/b/1/clang-x86_64-debian-fast/llvm.src/llvm/include/llvm/CodeGen/SelectionDAGNodes.h:2292:19: warning: HTML tag 'a' requires an end tag [-Wdocumentation-html]
  /// the value "<a,n>" is returned.
                  ^
/b/1/clang-x86_64-debian-fast/llvm.src/llvm/include/llvm/CodeGen/SelectionDAGNodes.h:2291:9: warning: HTML tag 'a' requires an end tag [-Wdocumentation-html]
  /// "<a, a+n, a+2n, a+3n, ...>" where a is integer and n is a non-zero integer,
        ^
In file included from /b/1/clang-x86_64-debian-fast/llvm.src/llvm/lib/Target/AArch64/AArch64TargetTransformInfo.cpp:9:
In file included from /b/1/clang-x86_64-debian-fast/llvm.src/llvm/lib/Target/AArch64/AArch64TargetTransformInfo.h:20:
In file included from /b/1/clang-x86_64-debian-fast/llvm.src/llvm/lib/Target/AArch64/AArch64Subtarget.h:17:
In file included from /b/1/clang-x86_64-debian-fast/llvm.src/llvm/lib/Target/AArch64/AArch64ISelLowering.h:20:
/b/1/clang-x86_64-debian-fast/llvm.src/llvm/include/llvm/CodeGen/TargetLowering.h:5453:14: warning: parameter 'N' not found in the function declaration [-Wdocumentation]
  /// \param N Node to expand
             ^
In file included from /b/1/clang-x86_64-debian-fast/llvm.src/llvm/lib/Target/AArch64/AArch64TargetTransformInfo.cpp:9:
In file included from /b/1/clang-x86_64-debian-fast/llvm.src/llvm/lib/Target/AArch64/AArch64TargetTransformInfo.h:20:
In file included from /b/1/clang-x86_64-debian-fast/llvm.src/llvm/lib/Target/AArch64/AArch64Subtarget.h:19:
/b/1/clang-x86_64-debian-fast/llvm.src/llvm/lib/Target/AArch64/AArch64PointerAuth.h:39:12: warning: HTML tag 'code' requires an end tag [-Wdocumentation-html]
///   brk <code>
          ~^~~~~
In file included from /b/1/clang-x86_64-debian-fast/llvm.src/llvm/lib/Target/AArch64/AArch64TargetTransformInfo.cpp:9:
In file included from /b/1/clang-x86_64-debian-fast/llvm.src/llvm/lib/Target/AArch64/AArch64TargetTransformInfo.h:23:
/b/1/clang-x86_64-debian-fast/llvm.src/llvm/include/llvm/CodeGen/BasicTTIImpl.h:3159:14: warning: parameter 'CondTy' not found in the function declaration [-Wdocumentation]
  /// \param CondTy Conditional type for the Select instruction.
             ^~~~~~
/b/1/clang-x86_64-debian-fast/llvm.src/llvm/lib/Target/AArch64/AArch64TargetTransformInfo.cpp:4420:31: error: redefinition of 'Cost' with a different type: 'llvm::InstructionCost' vs 'auto'
              InstructionCost Cost =

```

</details>

https://github.com/llvm/llvm-project/pull/150033