[opaque pointer type] Add textual IR support for explicit type parameter to load instruction

Essentially the same as the GEP change in r230786.

A similar migration script can be used to update test cases, though a few more
test case improvements/changes were required this time around: (r229269-r229278)

import fileinput
import sys
import re

pat = re.compile(r"((?:=|:|^)\s*load (?:atomic )?(?:volatile )?(.*?))(| addrspace\(\d+\) *)\*($| *(?:%|@|null|undef|blockaddress|getelementptr|addrspacecast|bitcast|inttoptr|\[\[[a-zA-Z]|\{\{).*$)")

for line in sys.stdin:
  sys.stdout.write(re.sub(pat, r"\1, \2\3*\4", line))

Reviewers: rafael, dexonsmith, grosser

Differential Revision: http://reviews.llvm.org/D7649

llvm-svn: 230794
diff --git a/llvm/test/DebugInfo/X86/byvalstruct.ll b/llvm/test/DebugInfo/X86/byvalstruct.ll
index d89ba35..794f417 100644
--- a/llvm/test/DebugInfo/X86/byvalstruct.ll
+++ b/llvm/test/DebugInfo/X86/byvalstruct.ll
@@ -74,7 +74,7 @@
   call void @llvm.dbg.declare(metadata %struct.ImageInfo* %info, metadata !33, metadata !{!"0x102"}), !dbg !34
   store i64 %length, i64* %length.addr, align 8
   call void @llvm.dbg.declare(metadata i64* %length.addr, metadata !35, metadata !{!"0x102"}), !dbg !36
-  %0 = load i8** %retval, !dbg !37
+  %0 = load i8*, i8** %retval, !dbg !37
   ret i8* %0, !dbg !37
 }