Silence some compiler warnings.

src/p_lx_interp.cpp

@@ -82,7 +82,7 @@ void PackLinuxElf32x86interp::pack1(OutputFile *fo, Filter &)
     assert(ehdri.e_phoff == sizeof(Elf32_Ehdr));  // checked by canPack()
     sz_phdrs = ehdri.e_phnum * ehdri.e_phentsize;
 
-    phdri = new Elf32_Phdr[(unsigned)ehdri.e_phnum];
+    phdri = New(Elf32_Phdr, ehdri.e_phnum);
     fi->seek(ehdri.e_phoff, SEEK_SET);
     fi->readx(phdri, sz_phdrs);