[RISCV] Define __riscv_cmodel_medlow and __riscv_cmodel_medany correctly

RISC-V LLVM was only implement small/medlow code model, so it defined
__riscv_cmodel_medlow directly without check.

Now, we have medium/medany code model in RISC-V back-end, it should
define according the actually code model.

Reviewed By: lewis-revill

Differential Revision: https://reviews.llvm.org/D67065

llvm-svn: 372078
diff --git a/clang/lib/Basic/Targets/RISCV.cpp b/clang/lib/Basic/Targets/RISCV.cpp
index 0a8df86..ab8272c 100644
--- a/clang/lib/Basic/Targets/RISCV.cpp
+++ b/clang/lib/Basic/Targets/RISCV.cpp
@@ -88,8 +88,14 @@
   Builder.defineMacro("__riscv");
   bool Is64Bit = getTriple().getArch() == llvm::Triple::riscv64;
   Builder.defineMacro("__riscv_xlen", Is64Bit ? "64" : "32");
-  // TODO: modify when more code models are supported.
-  Builder.defineMacro("__riscv_cmodel_medlow");
+  StringRef CodeModel = getTargetOpts().CodeModel;
+  if (CodeModel == "default")
+    CodeModel = "small";
+
+  if (CodeModel == "small")
+    Builder.defineMacro("__riscv_cmodel_medlow");
+  else if (CodeModel == "medium")
+    Builder.defineMacro("__riscv_cmodel_medany");
 
   StringRef ABIName = getABI();
   if (ABIName == "ilp32f" || ABIName == "lp64f")