[DWARFYAML][test] Use --ignore-case to suppress errors.

This patch is to fix build bot failure (http://lab.llvm.org:8011/builders/llvm-clang-win-x-aarch64/builds/553).
diff --git a/llvm/test/tools/yaml2obj/ELF/DWARF/debug-gnu-pubnames.yaml b/llvm/test/tools/yaml2obj/ELF/DWARF/debug-gnu-pubnames.yaml
index 4de8cd08..71c7981 100644
--- a/llvm/test/tools/yaml2obj/ELF/DWARF/debug-gnu-pubnames.yaml
+++ b/llvm/test/tools/yaml2obj/ELF/DWARF/debug-gnu-pubnames.yaml
@@ -236,7 +236,7 @@
 
 ## h) Test that yaml2obj emits an error if 'Descriptor' is missing.
 
-# RUN: not yaml2obj --docnum=8 %s -o %t8.o 2>&1 | FileCheck %s --check-prefix=MISSING-KEY
+# RUN: not yaml2obj --docnum=8 %s -o %t8.o 2>&1 | FileCheck %s --check-prefix=MISSING-KEY --ignore-case
 
 #      MISSING-KEY: YAML:260:9: error: missing required key 'Descriptor'
 # MISSING-KEY-NEXT:       - DieOffset: 0x12345678
diff --git a/llvm/test/tools/yaml2obj/ELF/DWARF/debug-gnu-pubtypes.yaml b/llvm/test/tools/yaml2obj/ELF/DWARF/debug-gnu-pubtypes.yaml
index e77417a..b88d21b 100644
--- a/llvm/test/tools/yaml2obj/ELF/DWARF/debug-gnu-pubtypes.yaml
+++ b/llvm/test/tools/yaml2obj/ELF/DWARF/debug-gnu-pubtypes.yaml
@@ -236,7 +236,7 @@
 
 ## h) Test that yaml2obj emits an error if 'Descriptor' is missing.
 
-# RUN: not yaml2obj --docnum=8 %s -o %t8.o 2>&1 | FileCheck %s --check-prefix=MISSING-KEY
+# RUN: not yaml2obj --docnum=8 %s -o %t8.o 2>&1 | FileCheck %s --check-prefix=MISSING-KEY --ignore-case
 
 #      MISSING-KEY: YAML:260:9: error: missing required key 'Descriptor'
 # MISSING-KEY-NEXT:       - DieOffset: 0x12345678