unittests: fix -Wnarrowing build errors

src/common/dwarf_cu_to_module.h

Index: src/common/dwarf_cu_to_module.h
diff --git a/src/common/dwarf_cu_to_module.h b/src/common/dwarf_cu_to_module.h
index fd9c380d9d8bbd48628fd387ee15b9049afd8e89..24243f1f31e104f2faf4b7a580c540a66771b567 100644
--- a/src/common/dwarf_cu_to_module.h
+++ b/src/common/dwarf_cu_to_module.h
@@ -84,7 +84,7 @@ class DwarfCUToModule: public dwarf2reader::RootDIEHandler {
 
     // Add CONTENTS of size LENGTH to the section map as NAME.
     void AddSectionToSectionMap(const string& name,
-                                const char* contents,
+                                const uint8_t *contents,
                                 uint64 length);
 
     // Clear the section map for testing.
@@ -140,7 +140,7 @@ class DwarfCUToModule: public dwarf2reader::RootDIEHandler {
     // mappings, given a pointer to some DWARF line number data
     // PROGRAM, and an overestimate of its size. Add no zero-length
     // lines to LINES.
-    virtual void ReadProgram(const char *program, uint64 length,
+    virtual void ReadProgram(const uint8_t *program, uint64 length,
                              Module *module, vector<Module::Line> *lines) = 0;
   };