VS2013 compiler OOM building api.ir

PR #3979 introduced this build failure (was not noticed b/c the build was red for another reason which distracted from this):

https://ci.appveyor.com/project/DynamoRIO/dynamorio/builds/29508076

debug-internal-32: **** 1 build errors ****
	c:\projects\dynamorio\suite\tests\api\ir_x86.c(463) : fatal error C1002: compiler is out of heap space in pass 2

One option is to finish up the VS2017 switch #2924 (closed). Another is to try to tweak the macros to work around this compiler problem.