GP-6479 improve DWARF's handling of stuff with a zeroed out address

Typically will be funcs or global vars that just have 0 for their lowpc
or the result of a expression that just hard codes DW_OP_addr 0.

Ghidra/Features/Base/src/main/java/ghidra/app/util/bin/format/dwarf/DWARFFunction.java

@@ -366,6 +366,14 @@ public class DWARFFunction {
 	public boolean syncWithExistingGhidraFunction(boolean createIfMissing) {
 		try {
 			Program currentProgram = getProgram().getGhidraProgram();
+			if (!currentProgram.getMemory().getExecuteSet().contains(address)) {
+				// NOTE: if func's DIE specifies a lowpc == 0, the calculated address will be
+				// the program's imagebase.  This typically can only be valid in .o files.
+				// If this binary is not a .o, and doesn't have executable segment at '0'
+				// (or where ever the binary was imported at), then the addr = 0 is probably
+				// just bad data that the toolchain put into the dwarf info.
+				return false; // dwarf function address info is probably bogus   
+			}
 			function = currentProgram.getListing().getFunctionAt(address);
 			if (function != null) {
 				if (function.hasNoReturn() && !noReturn) {

Ghidra/Features/Base/src/main/java/ghidra/app/util/bin/format/dwarf/DWARFFunctionImporter.java

@@ -388,6 +388,11 @@ public class DWARFFunctionImporter {
 		Namespace namespace = globalVar.name.getParentNamespace(currentProgram);
 		String name = globalVar.name.getName();
 		Address address = globalVar.getRamAddress();
+		if (prog.isZeroDataAddress(address)) {
+			// skip, its probably an incomplete DIE with a zero-d out location / address
+			// we can't create a bookmark with a warning since we don't have a good address.
+			return;
+		}
 		DataType dataType = globalVar.type;
 
 		SymbolTable symbolTable = currentProgram.getSymbolTable();

Ghidra/Features/Base/src/main/java/ghidra/app/util/bin/format/dwarf/DWARFProgram.java

@@ -617,6 +617,11 @@ public class DWARFProgram implements Closeable {
 				.getAddress(offset + programBaseAddressFixup, true);
 	}
 
+	public boolean isZeroDataAddress(Address addr) {
+		Address realZero = getDataAddress(0);
+		return realZero.equals(addr);
+	}
+
 	public boolean stackGrowsNegative() {
 		return stackGrowsNegative;
 	}