Spelling fix.

git-svn-id: https://svn.r-project.org/R/trunk@86480 00db46b3-68df-0310-9c12-caf00c1e9a41

Author: luke

src/include/Defn.h

@@ -2408,7 +2408,7 @@ extern void *alloca(size_t);
 // for reproducibility for now: use exp10 or pown later if accurate enough.
 #define Rexp10(x) pow(10.0, x)
 
-// this produces an initialized structure as a _compount literal_
+// this produces an initialized structure as a _compound literal_
 #define SEXP_TO_STACKVAL(x) ((R_bcstack_t) { .tag = 0, .u.sxpval = (x) })
 
 #endif /* DEFN_H_ */