Fix test failure created by ef8c913

Followup to https://reviews.llvm.org/D108877 to fix test
failure.

Author: sbc100

lld/test/wasm/shared-needed.s

@@ -29,7 +29,6 @@ data:
 # SO1-NEXT:     TableSize:       0
 # SO1-NEXT:     TableAlignment:  0
 # SO1-NEXT:     Needed:          []
-# SO1-NEXT:     ExportInfo:      []
 # SO1-NEXT:   - Type:            TYPE
 
 # SO2:      Sections:
@@ -41,5 +40,4 @@ data:
 # SO2-NEXT:     TableAlignment:  0
 # SO2-NEXT:     Needed:
 # SO2-NEXT:       - shared-needed.s.tmp1.so
-# SO2-NEXT:     ExportInfo:      []
 # SO2-NEXT:   - Type:            TYPE

lld/test/wasm/shared.s

@@ -133,7 +133,6 @@ get_local_func_address:
 # CHECK-NEXT:     TableSize:       2
 # CHECK-NEXT:     TableAlignment:  0
 # CHECK-NEXT:     Needed:          []
-# CHECK-NEXT:     ExportInfo:      []
 # CHECK-NEXT:   - Type:            TYPE
 
 # check for import of __table_base and __memory_base globals

lld/test/wasm/shared64.s

@@ -134,7 +134,6 @@ get_local_func_address:
 # CHECK-NEXT:     TableSize:       2
 # CHECK-NEXT:     TableAlignment:  0
 # CHECK-NEXT:     Needed:          []
-# CHECK-NEXT:     ExportInfo:      []
 # CHECK-NEXT:   - Type:            TYPE
 
 # check for import of __table_base and __memory_base globals

llvm/lib/ObjectYAML/WasmYAML.cpp

@@ -55,7 +55,7 @@ static void sectionMapping(IO &IO, WasmYAML::DylinkSection &Section) {
   IO.mapRequired("TableSize", Section.TableSize);
   IO.mapRequired("TableAlignment", Section.TableAlignment);
   IO.mapRequired("Needed", Section.Needed);
-  IO.mapRequired("ExportInfo", Section.ExportInfo);
+  IO.mapOptional("ExportInfo", Section.ExportInfo);
 }
 
 static void sectionMapping(IO &IO, WasmYAML::NameSection &Section) {