clang++: revert to --rtlib=libgcc

We previously patched clang to default to --rtlib=compiler-rt, but
this caused problems; revert to upstream default.

Change cfe-008-remove-lgcc-when-using-compiler-rt to only remove
-lgcc_s (which is superseded by compiler-rt), but keep -lgcc_eh which
is required for unwinding; else -lgcc_s is searched for -static
builds, causing failure.

This should fix build of C++ programs using exceptions on both glibc
and musl, and also should fix using --rtlib=compiler-rt on these
platforms.

Closes #2042.

srcpkgs/llvm/files/patches/cfe/cfe-002-default-runtime-compiler-rt.patch

@@ -1,27 +0,0 @@
-diff --git lib/Driver/ToolChains.cpp lib/Driver/ToolChains.cpp
-index f789fd5..07fc182 100644
---- lib/Driver/ToolChains.cpp
-+++ lib/Driver/ToolChains.cpp
-@@ -3385,6 +3385,10 @@ void Linux::AddClangCXXStdlibIncludeArgs(const ArgList &DriverArgs,
-   }
- }
- 
-+ToolChain::RuntimeLibType Linux::GetDefaultRuntimeLibType() const {
-+  return ToolChain::RLT_CompilerRT;
-+}
-+
- bool Linux::isPIEDefault() const {
-   return getSanitizerArgs().requiresPIE();
- }
-diff --git lib/Driver/ToolChains.h lib/Driver/ToolChains.h
-index 47fb10d..88aee51 100644
---- lib/Driver/ToolChains.h
-+++ lib/Driver/ToolChains.h
-@@ -640,6 +640,7 @@ public:
-   void
-   AddClangCXXStdlibIncludeArgs(const llvm::opt::ArgList &DriverArgs,
-                                llvm::opt::ArgStringList &CC1Args) const override;
-+  RuntimeLibType GetDefaultRuntimeLibType() const override;
-   bool isPIEDefault() const override;
- 
-   std::string Linker;

srcpkgs/llvm/files/patches/cfe/cfe-008-remove-lgcc-when-using-compiler-rt.patch

@@ -1,23 +1,11 @@
-diff --git lib/Driver/Tools.cpp lib/Driver/Tools.cpp
-index 5a5cba7..701ac12 100644
---- lib/Driver/Tools.cpp
-+++ lib/Driver/Tools.cpp
-@@ -2157,12 +2157,12 @@ static void addClangRT(const ToolChain &TC, const ArgList &Args,
-                        ArgStringList &CmdArgs) {
+--- lib/Driver/Tools.cpp	2015-08-11 13:59:22.324639527 +0200
++++ lib/Driver/Tools.cpp	2015-08-11 13:59:34.058576064 +0200
+@@ -2158,8 +2158,6 @@
    CmdArgs.push_back(Args.MakeArgString(getCompilerRT(TC, "builtins")));
  
--  if (!TC.getTriple().isOSWindows()) {
+   if (!TC.getTriple().isOSWindows()) {
 -    // FIXME: why do we link against gcc when we are using compiler-rt?
 -    CmdArgs.push_back("-lgcc_s");
--    if (TC.getDriver().CCCIsCXX())
--      CmdArgs.push_back("-lgcc_eh");
--  }
-+  // if (!TC.getTriple().isOSWindows()) {
-+  //   // FIXME: why do we link against gcc when we are using compiler-rt?
-+  //   CmdArgs.push_back("-lgcc_s");
-+  //   if (TC.getDriver().CCCIsCXX())
-+  //     CmdArgs.push_back("-lgcc_eh");
-+  // }
- }
- 
- static void addProfileRT(const ToolChain &TC, const ArgList &Args,
+     if (TC.getDriver().CCCIsCXX())
+       CmdArgs.push_back("-lgcc_eh");
+   }

srcpkgs/llvm/template

@@ -1,7 +1,7 @@
 # Template file for 'llvm'
 pkgname=llvm
 version=3.6.2
-revision=1
+revision=2
 wrksrc="llvm-${version}.src"
 lib32disabled=yes
 configure_args="--disable-expensive-checks --disable-debug-runtime