[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/Mips/hf1_body.ll b/llvm/test/CodeGen/Mips/hf1_body.ll
index 5acfe86..71a1b96 100644
--- a/llvm/test/CodeGen/Mips/hf1_body.ll
+++ b/llvm/test/CodeGen/Mips/hf1_body.ll
@@ -7,7 +7,7 @@
 entry:
   %p.addr = alloca float, align 4
   store float %p, float* %p.addr, align 4
-  %0 = load float* %p.addr, align 4
+  %0 = load float, float* %p.addr, align 4
   store float %0, float* @x, align 4
   ret void
 }