build: use clang instead of llvm-gcc (#300)

Modern clang works just fine, also llvm-gcc is nowhere to be found.

Author: ryan-filmware

Make.inc

@@ -39,6 +39,7 @@ endif
 
 ifeq ($(ARCH),wasm32)
 USECLANG = 1
+USEGCC = 0
 TOOLPREFIX = llvm-
 endif
 

README.md

@@ -29,7 +29,7 @@ loongarch64.
    Linux and Windows.
 3. Use `make USECLANG=1` to build with clang. This is the default on OS X, FreeBSD,
    and OpenBSD.
-4. Use `make ARCH=wasm32` to build the wasm32 library with clang. Requires clang-8.
+4. Use `make ARCH=wasm32` to build the wasm32 library with clang.
 5. Architectures are auto-detected. Use `make ARCH=i386` to force a
    build for i386. Other supported architectures are i486, i586, and
    i686. GCC 4.8 is the minimum requirement for correct codegen on