[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/CodeGen/PowerPC/emptystruct.ll b/llvm/test/CodeGen/PowerPC/emptystruct.ll
index 47cfadd..66cada1 100644
--- a/llvm/test/CodeGen/PowerPC/emptystruct.ll
+++ b/llvm/test/CodeGen/PowerPC/emptystruct.ll
@@ -18,7 +18,7 @@
 entry:
   %a2.addr = alloca %struct.empty*, align 8
   store %struct.empty* %a2, %struct.empty** %a2.addr, align 8
-  %0 = load %struct.empty** %a2.addr, align 8
+  %0 = load %struct.empty*, %struct.empty** %a2.addr, align 8
   %1 = bitcast %struct.empty* %agg.result to i8*
   %2 = bitcast %struct.empty* %0 to i8*
   call void @llvm.memcpy.p0i8.p0i8.i64(i8* %1, i8* %2, i64 0, i32 1, i1 false)