[llvm][docs] Update old metadata syntax in examples

This patch updates examples in the documentation to match the existing
convention. Calls to intrinsics that have metadata arguments were not
included.

Reviewed By: dexonsmith

Differential Revision: https://reviews.llvm.org/D142651

llvm/docs/BlockFrequencyTerminology.rst

@@ -37,7 +37,7 @@ For example, consider this IR:
            br i1 %cond, label %B, label %C, !prof !0
        ; ...
    }
-   !0 = metadata !{metadata !"branch_weights", i32 7, i32 8}
+   !0 = !{!"branch_weights", i32 7, i32 8}
 
 and this simple graph representation::
 

llvm/docs/BranchWeightMetadata.rst

@@ -31,8 +31,8 @@ operands for the true and the false branch.
 
 .. code-block:: none
 
-  !0 = metadata !{
-    metadata !"branch_weights",
+  !0 = !{
+    !"branch_weights",
     i32 <TRUE_BRANCH_WEIGHT>,
     i32 <FALSE_BRANCH_WEIGHT>
   }
@@ -45,8 +45,8 @@ is always case #0).
 
 .. code-block:: none
 
-  !0 = metadata !{
-    metadata !"branch_weights",
+  !0 = !{
+    !"branch_weights",
     i32 <DEFAULT_BRANCH_WEIGHT>
     [ , i32 <CASE_BRANCH_WEIGHT> ... ]
   }
@@ -58,8 +58,8 @@ Branch weights are assigned to every destination.
 
 .. code-block:: none
 
-  !0 = metadata !{
-    metadata !"branch_weights",
+  !0 = !{
+    !"branch_weights",
     i32 <LABEL_BRANCH_WEIGHT>
     [ , i32 <LABEL_BRANCH_WEIGHT> ... ]
   }
@@ -73,8 +73,8 @@ block and entry counts which may not be accurate with sampling.
 
 .. code-block:: none
 
-  !0 = metadata !{
-    metadata !"branch_weights",
+  !0 = !{
+    !"branch_weights",
     i32 <CALL_BRANCH_WEIGHT>
   }
 
@@ -93,8 +93,8 @@ is used.
 
 .. code-block:: none
 
-  !0 = metadata !{
-    metadata !"branch_weights",
+  !0 = !{
+    !"branch_weights",
     i32 <INVOKE_NORMAL_WEIGHT>
     [ , i32 <INVOKE_UNWIND_WEIGHT> ]
   }