Test for the presence of a bunch of new macros for c++17. These macros come from C11. Part of P0063

llvm-svn: 338454
Cr-Mirrored-From: sso://chromium.googlesource.com/_direct/external/github.com/llvm/llvm-project
Cr-Mirrored-Commit: 5802ab265cd36c0f75cbe906c3f2ca5addc9e48d
diff --git a/include/float.h b/include/float.h
index 1acfdc6..759ac8e 100644
--- a/include/float.h
+++ b/include/float.h
@@ -24,7 +24,14 @@
     DBL_MANT_DIG
     LDBL_MANT_DIG
 
+    FLT_HAS_SUBNORM     // C11
+    DBL_HAS_SUBNORM     // C11
+    LDBL_HAS_SUBNORM    // C11
+
     DECIMAL_DIG         // C99
+    FLT_DECIMAL_DIG     // C11
+    DBL_DECIMAL_DIG     // C11
+    LDBL_DECIMAL_DIG    // C11
 
     FLT_DIG
     DBL_DIG
@@ -58,6 +65,10 @@
     DBL_MIN
     LDBL_MIN
 
+    FLT_TRUE_MIN        // C11
+    DBL_TRUE_MIN        // C11
+    LDBL_TRUE_MIN       // C11
+
 */
 
 #include <__config>