[clang][test] Require x86 target for new Windows EH tests

Added by #144745.

These tests cause Clang -cc1 to generate the option
-x86-asm-syntax=intel, which is only available if you have
included the x86 target.

<<<<<<
            1: clang: warning: argument unused during compilation: '-c' [-Wunused-command-line-argument]
label:38'0     X~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ error: no match found
label:38'1                                                                   ?                            possible intended match
            2: clang (LLVM option parsing): Unknown command line argument '-x86-asm-syntax=intel'. Try: 'clang (LLVM option parsing) --help'
label:38'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
            3: clang (LLVM option parsing): Did you mean '--asan-stack=intel'?
label:38'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>>>>>>

Author: DavidSpickett

clang/test/CodeGenCXX/microsoft-abi-eh-disabled.cpp

@@ -1,3 +1,4 @@
+// REQUIRES: x86-registered-target
 // RUN: %clang_cl -c --target=x86_64-windows-msvc -EHs-c- -O2 -GS- \
 // RUN:   -Xclang=-import-call-optimization \
 // RUN:   -clang:-S -clang:-o- -- %s 2>&1 \

clang/test/CodeGenCXX/microsoft-abi-eh-ip2state.cpp

@@ -1,3 +1,4 @@
+// REQUIRES: x86-registered-target
 // RUN: %clang_cl -c --target=x86_64-windows-msvc -O2 -EHsc -GS- \
 // RUN:   -Xclang=-import-call-optimization \
 // RUN:   -clang:-S -clang:-o- -- %s 2>&1 \