[FPEnv] Divide macro INSTRUCTION into INSTRUCTION and DAG_INSTRUCTION,
and macro FUNCTION likewise. NFCI.

Some functions like fmuladd don't really have a node, we should divide
the declaration form those have node to avoid introducing fake nodes.

Differential Revision: https://reviews.llvm.org/D72871
diff --git a/llvm/lib/IR/IntrinsicInst.cpp b/llvm/lib/IR/IntrinsicInst.cpp
index b23742b..78f98fd 100644
--- a/llvm/lib/IR/IntrinsicInst.cpp
+++ b/llvm/lib/IR/IntrinsicInst.cpp
@@ -149,7 +149,7 @@
   switch (getIntrinsicID()) {
     default:
       return false;
-#define INSTRUCTION(NAME, NARG, ROUND_MODE, INTRINSIC, DAGN)                   \
+#define INSTRUCTION(NAME, NARG, ROUND_MODE, INTRINSIC)                         \
     case Intrinsic::INTRINSIC:                                                 \
       return NARG == 1;
 #include "llvm/IR/ConstrainedOps.def"
@@ -160,7 +160,7 @@
   switch (getIntrinsicID()) {
     default:
       return false;
-#define INSTRUCTION(NAME, NARG, ROUND_MODE, INTRINSIC, DAGN)                   \
+#define INSTRUCTION(NAME, NARG, ROUND_MODE, INTRINSIC)                         \
     case Intrinsic::INTRINSIC:                                                 \
       return NARG == 3;
 #include "llvm/IR/ConstrainedOps.def"
@@ -169,7 +169,7 @@
 
 bool ConstrainedFPIntrinsic::classof(const IntrinsicInst *I) {
   switch (I->getIntrinsicID()) {
-#define INSTRUCTION(NAME, NARGS, ROUND_MODE, INTRINSIC, DAGN)                  \
+#define INSTRUCTION(NAME, NARGS, ROUND_MODE, INTRINSIC)                        \
   case Intrinsic::INTRINSIC:
 #include "llvm/IR/ConstrainedOps.def"
     return true;