[Docs][GlobalISel] Fix a long header in GenericOpcode (NFC) (#84976)

Author: e-kud

llvm/docs/GlobalISel/GenericOpcode.rst

@@ -790,11 +790,17 @@ G_ATOMIC_CMPXCHG
 Generic atomic cmpxchg. Expects a MachineMemOperand in addition to explicit
 operands.
 
-G_ATOMICRMW_XCHG, G_ATOMICRMW_ADD, G_ATOMICRMW_SUB, G_ATOMICRMW_AND,
-G_ATOMICRMW_NAND, G_ATOMICRMW_OR, G_ATOMICRMW_XOR, G_ATOMICRMW_MAX,
-G_ATOMICRMW_MIN, G_ATOMICRMW_UMAX, G_ATOMICRMW_UMIN, G_ATOMICRMW_FADD,
-G_ATOMICRMW_FSUB, G_ATOMICRMW_FMAX, G_ATOMICRMW_FMIN
-^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+|all_g_atomicrmw|
+^^^^^^^^^^^^^^^^^
+
+.. |all_g_atomicrmw| replace:: G_ATOMICRMW_XCHG, G_ATOMICRMW_ADD,
+                               G_ATOMICRMW_SUB, G_ATOMICRMW_AND,
+                               G_ATOMICRMW_NAND, G_ATOMICRMW_OR,
+                               G_ATOMICRMW_XOR, G_ATOMICRMW_MAX,
+                               G_ATOMICRMW_MIN, G_ATOMICRMW_UMAX,
+                               G_ATOMICRMW_UMIN, G_ATOMICRMW_FADD,
+                               G_ATOMICRMW_FSUB, G_ATOMICRMW_FMAX,
+                               G_ATOMICRMW_FMIN
 
 Generic atomicrmw. Expects a MachineMemOperand in addition to explicit
 operands.