Fix some escaping and quoting in RUN lines, mainly involving { and <. In two
cases quoting of <{ didn't work out, so I changed the grep to check for }>
instead.

This fixes 7 testcases that were not properly running before.

llvm-svn: 52182
diff --git a/llvm/test/Integer/packed_struct_bt.ll b/llvm/test/Integer/packed_struct_bt.ll
index 3713917..a4d01e7 100644
--- a/llvm/test/Integer/packed_struct_bt.ll
+++ b/llvm/test/Integer/packed_struct_bt.ll
@@ -2,7 +2,7 @@
 ; RUN: llvm-as %t1.ll -o - | llvm-dis > %t2.ll
 ; RUN: diff %t1.ll %t2.ll
 ; RUN: not grep cast %t2.ll
-; RUN: grep {\<\{} %t2.ll
+; RUN: grep {\\}>} %t2.ll
 ; END.
 
 %struct.anon = type <{ i8, i35, i35, i35 }>