[clang] Prune 'IsOMPStructuredBlock' Stmt bit
As discussed in https://reviews.llvm.org/D59214#1916596
and in some other reviews dealing with FPenv,
bits in Stmt are scarce, and i got so burnout with D59214
and https://bugs.llvm.org/show_bug.cgi?id=40563 specifically
that i never actually followed up with the usages for this bit.
So let's unhoard it, at least for now?
diff --git a/clang/test/AST/ast-dump-openmp-parallel.c b/clang/test/AST/ast-dump-openmp-parallel.c
index ff599d6..0a72a9c 100644
--- a/clang/test/AST/ast-dump-openmp-parallel.c
+++ b/clang/test/AST/ast-dump-openmp-parallel.c
@@ -11,7 +11,7 @@
// CHECK-NEXT: `-OMPParallelDirective {{.*}} <line:4:1, col:21>
// CHECK-NEXT: `-CapturedStmt {{.*}} <line:5:3>
// CHECK-NEXT: `-CapturedDecl {{.*}} <<invalid sloc>> <invalid sloc> nothrow
-// CHECK-NEXT: |-NullStmt {{.*}} <col:3> openmp_structured_block
+// CHECK-NEXT: |-NullStmt {{.*}} <col:3>
// CHECK-NEXT: |-ImplicitParamDecl {{.*}} <line:4:1> col:1 implicit .global_tid. 'const int *const restrict'
// CHECK-NEXT: |-ImplicitParamDecl {{.*}} <col:1> col:1 implicit .bound_tid. 'const int *const restrict'
// CHECK-NEXT: `-ImplicitParamDecl {{.*}} <col:1> col:1 implicit __context 'struct (anonymous at {{.*}}ast-dump-openmp-parallel.c:4:1) *const restrict'