clang: fix check for realloc pointer argument

The previous check, in sema, would look at the section of realloc, not
the one of the calling function.
This would both miss detection of issue for genericjs uses, and falsely
flag asmjs uses with the upcoming commit intruducing #pragma cheerp

clang/include/clang/Sema/Sema.h

@@ -13372,7 +13372,6 @@ class Sema final {
 
   bool CheckAArch64BuiltinFunctionCall(const TargetInfo &TI, unsigned BuiltinID,
                                        CallExpr *TheCall);
-  bool CheckCheerpBuiltinFunctionCall(unsigned BuiltinID, CallExpr *TheCall);
   bool CheckBPFBuiltinFunctionCall(unsigned BuiltinID, CallExpr *TheCall);
   bool CheckHexagonBuiltinFunctionCall(unsigned BuiltinID, CallExpr *TheCall);
   bool CheckHexagonBuiltinArgument(unsigned BuiltinID, CallExpr *TheCall);

clang/lib/CodeGen/CGBuiltin.cpp

@@ -12738,11 +12738,12 @@ Value *CodeGenFunction::EmitCheerpBuiltinExpr(unsigned BuiltinID,
     // There must be an incoming cast, void* are not directly accepted
     const CastExpr* argCE=dyn_cast<CastExpr>(E->getArg(0));
 
-    if (asmjs && (!argCE || argCE->getSubExpr()->getType()->isVoidPointerType()))
+    if (!argCE || argCE->getSubExpr()->getType()->isVoidPointerType()) {
+      if (!asmjs)
+        CGM.getDiags().Report(E->getArg(0)->getBeginLoc(), diag::err_cheerp_memintrinsic_type_unknown);
       return 0;
+    }
 
-    // This condition is verified in Sema
-    assert(argCE && !argCE->getSubExpr()->getType()->isVoidPointerType());
     //TODO: realloc can be invoked with NULL, support that
     const Expr* existingMem=argCE->getSubExpr();
     // The type for the realloc is decided from the base type

clang/lib/Sema/SemaChecking.cpp

@@ -2692,13 +2692,6 @@ Sema::CheckBuiltinFunctionCall(FunctionDecl *FDecl, unsigned BuiltinID,
   }
   }
 
-  bool asmjs = FDecl->hasAttr<AsmJSAttr>();
-  // Some builtins need special handling on generic Cheerp
-  if (!asmjs && Context.getTargetInfo().getTriple().getArch()==llvm::Triple::cheerp) {
-    if (CheckCheerpBuiltinFunctionCall(BuiltinID, TheCall))
-      return ExprError();
-  }
-
   // Since the target specific builtins for each arch overlap, only check those
   // of the arch we are compiling for.
   if (Context.BuiltinInfo.isTSBuiltin(BuiltinID)) {
@@ -5484,19 +5477,6 @@ bool Sema::CheckX86BuiltinFunctionCall(const TargetInfo &TI, unsigned BuiltinID,
   return SemaBuiltinConstantArgRange(TheCall, i, l, u, /*RangeIsError*/ false);
 }
 
-bool Sema::CheckCheerpBuiltinFunctionCall(unsigned BuiltinID, CallExpr *TheCall) {
-    if (BuiltinID == Builtin::BIrealloc) {
-      const CastExpr* argCE=dyn_cast<CastExpr>(TheCall->getArg(0));
-      if (!argCE || argCE->getSubExpr()->getType()->isVoidPointerType())
-      {
-        Diag(TheCall->getArg(0)->getBeginLoc(), diag::err_cheerp_memintrinsic_type_unknown);
-        return true;
-      }
-      // NOTE: It's not possible to analyze the return type here since we can't build the parent map
-    }
-    return false;
-}
-
 /// Given a FunctionDecl's FormatAttr, attempts to populate the FomatStringInfo
 /// parameter with the FormatAttr's correct format_idx and firstDataArg.
 /// Returns true when the format fits the function and the FormatStringInfo has