Add support for RISC-V

double-conversion/utils.h

diff --git a/double-conversion/utils.h b/double-conversion/utils.h
index 51d5e61..2c745f3 100644
--- a/double-conversion/utils.h
+++ b/double-conversion/utils.h
@@ -76,7 +76,8 @@
     defined(__sparc__) || defined(__sparc) || defined(__s390__) || \
     defined(__SH4__) || defined(__alpha__) || \
     defined(_MIPS_ARCH_MIPS32R2) || \
-    defined(__AARCH64EL__) || defined(__aarch64__)
+    defined(__AARCH64EL__) || defined(__aarch64__) || \
+    defined(__riscv)
 #define DOUBLE_CONVERSION_CORRECT_DOUBLE_OPERATIONS 1
 #elif defined(__mc68000__)
 #undef DOUBLE_CONVERSION_CORRECT_DOUBLE_OPERATIONS