[LLD][NFC] Don't use x64 import library for x86 target in safeseh-md tests. (#102736)

Use llvm-lib to generate input library instead of a binary blob.

Author: cjacek

lld/test/COFF/Inputs/except_handler3.lib

@@ -1,12 +1,15 @@
 # REQUIRES: x86
-# RUN: llvm-mc -triple i686-windows-msvc %s -filetype=obj -o %t.obj
-# RUN: lld-link %t.obj %S/Inputs/except_handler3.lib -safeseh -out:%t.exe -opt:noref -entry:main
+# RUN: split-file %s %t.dir
+# RUN: llvm-mc -triple i686-windows-msvc %t.dir/safeseh-md.s -filetype=obj -o %t.obj
+# RUN: llvm-lib -machine:x86 -out:%t.dir/except_handler3.lib -def:%t.dir/except_handler3.def
+# RUN: lld-link %t.obj %t.dir/except_handler3.lib -safeseh -out:%t.exe -opt:noref -entry:main
 # RUN: llvm-readobj --coff-load-config %t.exe | FileCheck %s
 
 # CHECK: SEHTable [
 # CHECK-NEXT: 0x
 # CHECK-NEXT: ]
 
+#--- safeseh-md.s
         .def     @feat.00;
         .scl    3;
         .type   0;
@@ -33,3 +36,8 @@ __load_config_used:
         .fill 60, 1, 0
         .long ___safe_se_handler_table
         .long ___safe_se_handler_count
+
+#--- except_handler3.def
+NAME except_handler3.dll
+EXPORTS
+        _except_handler3