Fix some static analyzer issues (#1789)

Signed-off-by: Arvind Sudarsanam <[email protected]>

Original commit:
KhronosGroup/SPIRV-LLVM-Translator@a8b0c8e

Author: asudarsa

llvm-spirv/lib/SPIRV/SPIRVReader.cpp

@@ -3314,7 +3314,7 @@ void generateIntelFPGAAnnotation(
     Out << "{simple_dual_port:1}";
   if (E->hasDecorate(DecorationMergeINTEL)) {
     Out << "{merge";
-    for (auto Str : E->getDecorationStringLiteral(DecorationMergeINTEL))
+    for (const auto &Str : E->getDecorationStringLiteral(DecorationMergeINTEL))
       Out << ":" << Str;
     Out << '}';
   }
@@ -3396,8 +3396,8 @@ void generateIntelFPGAAnnotationForStructMember(
     Out << "{simple_dual_port:1}";
   if (E->hasMemberDecorate(DecorationMergeINTEL, 0, MemberNumber)) {
     Out << "{merge";
-    for (auto Str : E->getMemberDecorationStringLiteral(DecorationMergeINTEL,
-                                                        MemberNumber))
+    for (const auto &Str : E->getMemberDecorationStringLiteral(
+             DecorationMergeINTEL, MemberNumber))
       Out << ":" << Str;
     Out << '}';
   }

llvm-spirv/lib/SPIRV/libSPIRV/SPIRVModule.cpp

@@ -1810,7 +1810,7 @@ class TopologicalSort {
     for (auto *V : VariableVec)
       EntryStateMap[V] = DFSState::Unvisited;
     // Run topoligical sort
-    for (auto ES : EntryStateMap) {
+    for (const auto &ES : EntryStateMap) {
       if (visit(ES.first))
         llvm_unreachable("Cyclic dependency for types detected");
     }