[x86] Add tan intrinsic part 4  (#90503)

This change is an implementation of #87367's investigation on supporting
IEEE math operations as intrinsics.
Which was discussed in this RFC:
https://discourse.llvm.org/t/rfc-all-the-math-intrinsics/78294


Much of this change was following how G_FSIN and G_FCOS were used.

Changes:
- `llvm/docs/GlobalISel/GenericOpcode.rst` - Document the `G_FTAN`
opcode
-  `llvm/docs/LangRef.rst` - Document the tan intrinsic
- `llvm/include/llvm/Analysis/VecFuncs.def` - Associate the tan
intrinsic as a vector function similar to the tanf libcall.
- `llvm/include/llvm/CodeGen/BasicTTIImpl.h` - Map the tan intrinsic to
`ISD::FTAN`
- `llvm/include/llvm/CodeGen/ISDOpcodes.h` - Define ISD opcodes for
`FTAN` and `STRICT_FTAN`
-  `llvm/include/llvm/IR/Intrinsics.td` - Create the tan intrinsic
- `llvm/include/llvm/IR/RuntimeLibcalls.def` - Define tan libcall
mappings
- `llvm/include/llvm/Target/GenericOpcodes.td` - Define the `G_FTAN`
Opcode
- `llvm/include/llvm/Support/TargetOpcodes.def` - Create a `G_FTAN`
Opcode handler
- `llvm/include/llvm/Target/GlobalISel/SelectionDAGCompat.td` - Map
`G_FTAN` to `ftan`
- `llvm/include/llvm/Target/TargetSelectionDAG.td` - Define `ftan`,
`strict_ftan`, and `any_ftan` and map them to the ISD opcodes for `FTAN`
and `STRICT_FTAN`
- `llvm/lib/Analysis/VectorUtils.cpp` - Associate the tan intrinsic as a
vector intrinsic
- `llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp` Map the tan intrinsic
to `G_FTAN` Opcode
- `llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp` - Add `G_FTAN` to
the list of floating point math operations also associate `G_FTAN` with
the `TAN_F` runtime lib.
- `llvm/lib/CodeGen/GlobalISel/Utils.cpp` - More floating point math
operation common behaviors.
- llvm/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp - List the function
expansion operations for `FTAN` and `STRICT_FTAN`. Also define both
opcodes in `PromoteNode`.
- `llvm/lib/CodeGen/SelectionDAG/LegalizeFloatTypes.cpp` - More `FTAN`
and `STRICT_FTAN` handling in the legalizer
- `llvm/lib/CodeGen/SelectionDAG/LegalizeTypes.h` - Define
`SoftenFloatRes_FTAN` and `ExpandFloatRes_FTAN`.
- `llvm/lib/CodeGen/SelectionDAG/LegalizeVectorOps.cpp` - Define `FTAN`
as a legal vector operation.
- `llvm/lib/CodeGen/SelectionDAG/LegalizeVectorTypes.cpp` - Define
`FTAN` as a legal vector operation.
- `llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp` - define tan as an
intrinsic that doesn't return NaN.
- `llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp` Map
`LibFunc_tan`, `LibFunc_tanf`, and `LibFunc_tanl` to `ISD::FTAN`. Map
`Intrinsic::tan` to `ISD::FTAN` and add selection dag handling for
`Intrinsic::tan`.
- `llvm/lib/CodeGen/SelectionDAG/SelectionDAGDumper.cpp` - Define `ftan`
and `strict_ftan` names for the equivalent ISD opcodes.
- `llvm/lib/CodeGen/TargetLoweringBase.cpp` -Define a Tan128 libcall and
ISD::FTAN as a target lowering action.
- `llvm/lib/Target/X86/X86ISelLowering.cpp` - Add x86_64 lowering for
tan intrinsic

resolves https://github.com/llvm/llvm-project/issues/70082
diff --git a/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp b/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
index 6f0cae2..9830b52 100644
--- a/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
+++ b/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
@@ -449,6 +449,8 @@
     RTLIBCASE(SIN_F);
   case TargetOpcode::G_FCOS:
     RTLIBCASE(COS_F);
+  case TargetOpcode::G_FTAN:
+    RTLIBCASE(TAN_F);
   case TargetOpcode::G_FLOG10:
     RTLIBCASE(LOG10_F);
   case TargetOpcode::G_FLOG:
@@ -1037,6 +1039,7 @@
   case TargetOpcode::G_FREM:
   case TargetOpcode::G_FCOS:
   case TargetOpcode::G_FSIN:
+  case TargetOpcode::G_FTAN:
   case TargetOpcode::G_FLOG10:
   case TargetOpcode::G_FLOG:
   case TargetOpcode::G_FLOG2:
@@ -2893,6 +2896,7 @@
   case TargetOpcode::G_FFLOOR:
   case TargetOpcode::G_FCOS:
   case TargetOpcode::G_FSIN:
+  case TargetOpcode::G_FTAN:
   case TargetOpcode::G_FLOG10:
   case TargetOpcode::G_FLOG:
   case TargetOpcode::G_FLOG2:
@@ -4659,6 +4663,7 @@
   case G_INTRINSIC_TRUNC:
   case G_FCOS:
   case G_FSIN:
+  case G_FTAN:
   case G_FSQRT:
   case G_BSWAP:
   case G_BITREVERSE: