[Driver] Forward sysroot from Driver to linker in BareMetal ToolChain Object

RISCVToolChain object passes `--sysroot` option from clang to gnuld. Adding
the supprt for the same in BareMetal toolchain object.

This is done as a part of the effort to merge RISCVToolchain object into
BareMetal toolchain object.

This is the 5th patch in the series of patches for merging RISCVToolchain object
into BareMetal toolchain object.

RFC:
https://discourse.llvm.org/t/merging-riscvtoolchain-and-baremetal-toolchains/75524

Change-Id: Ie830bf6d126fea46dc225e5ef97e14349765ba07

Author: quic-garvgupt

Diff for: clang/lib/Driver/ToolChains/BareMetal.cpp

@@ -529,6 +529,9 @@ void baremetal::Linker::ConstructJob(Compilation &C, const JobAction &JA,
   const llvm::Triple::ArchType Arch = TC.getArch();
   const llvm::Triple &Triple = getToolChain().getEffectiveTriple();
 
+  if (!D.SysRoot.empty())
+    CmdArgs.push_back(Args.MakeArgString("--sysroot=" + D.SysRoot));
+
   CmdArgs.push_back("-Bstatic");
 
   if (TC.getTriple().isRISCV() && Args.hasArg(options::OPT_mno_relax))

Diff for: clang/test/Driver/aarch64-toolchain.c

@@ -17,6 +17,7 @@
 // C-AARCH64-BAREMETAL: "-isysroot" "{{.*}}Inputs/basic_aarch64_gcc_tree/aarch64-none-elf"
 // C-AARCH64-BAREMETAL: "-internal-isystem" "{{.*}}Inputs/basic_aarch64_gcc_tree/aarch64-none-elf/include"
 // C-AARCH64-BAREMETAL: "{{.*}}/Inputs/basic_aarch64_gcc_tree/lib/gcc/aarch64-none-elf/8.2.1/../../../../bin/aarch64-none-elf-ld"
+// C-AARCH64-BAREMETAL: "--sysroot={{.*}}/Inputs/basic_aarch64_gcc_tree/aarch64-none-elf"
 // C-AARCH64-BAREMETAL: "-Bstatic" "-EL"
 // C-AARCH64-BAREMETAL: "{{.*}}/Inputs/basic_aarch64_gcc_tree/aarch64-none-elf/lib/crt0.o"
 // C-AARCH64-BAREMETAL: "{{.*}}/Inputs/basic_aarch64_gcc_tree/lib/gcc/aarch64-none-elf/8.2.1/crtbegin.o"
@@ -53,6 +54,7 @@
 // CXX-AARCH64-BAREMETAL: "-internal-isystem" "{{.*}}/Inputs/basic_aarch64_gcc_tree/aarch64-none-elf/include/c++/8.2.1"
 // CXX-AARCH64-BAREMETAL: "-internal-isystem" "{{.*}}/Inputs/basic_aarch64_gcc_tree/aarch64-none-elf/include"
 // CXX-AARCH64-BAREMETAL: "{{.*}}/Inputs/basic_aarch64_gcc_tree/lib/gcc/aarch64-none-elf/8.2.1/../../../../bin/aarch64-none-elf-ld"
+// CXX-AARCH64-BAREMETAL: "--sysroot={{.*}}/Inputs/basic_aarch64_gcc_tree/aarch64-none-elf"
 // CXX-AARCH64-BAREMETAL: "-Bstatic" "-EL"
 // CXX-AARCH64-BAREMETAL: "{{.*}}/Inputs/basic_aarch64_gcc_tree/aarch64-none-elf/lib/crt0.o"
 // CXX-AARCH64-BAREMETAL: "{{.*}}/Inputs/basic_aarch64_gcc_tree/lib/gcc/aarch64-none-elf/8.2.1/crtbegin.o"
@@ -89,7 +91,8 @@
 // CXX-AARCH64-BAREMETAL-LIBCXX: "-isysroot" "{{.*}}Inputs/basic_aarch64_gcc_tree/aarch64-none-elf"
 // CXX-AARCH64-BAREMETAL-LIBCXX: "-internal-isystem" "{{.*}}/Inputs/basic_aarch64_gcc_tree/aarch64-none-elf/include/c++/v1"
 // CXX-AARCH64-BAREMETAL-LIBCXX: "-internal-isystem" "{{.*}}/Inputs/basic_aarch64_gcc_tree/aarch64-none-elf/include"
-// CXX-AARCH64-BAREMETAL-LIBCXX: "{{.*}}/Inputs/basic_aarch64_gcc_tree/lib/gcc/aarch64-none-elf/8.2.1/../../../../bin/aarch64-none-elf-ld
+// CXX-AARCH64-BAREMETAL-LIBCXX: "{{.*}}/Inputs/basic_aarch64_gcc_tree/lib/gcc/aarch64-none-elf/8.2.1/../../../../bin/aarch64-none-elf-ld"
+// CXX-AARCH64-BAREMETAL-LIBCXX: "--sysroot={{.*}}/Inputs/basic_aarch64_gcc_tree/aarch64-none-elf"
 // CXX-AARCH64-BAREMETAL-LIBCXX: "-Bstatic" "-EL"
 // CXX-AARCH64-BAREMETAL-LIBCXX: "{{.*}}/Inputs/basic_aarch64_gcc_tree/aarch64-none-elf/lib/crt0.o"
 // CXX-AARCH64-BAREMETAL-LIBCXX: "{{.*}}/Inputs/basic_aarch64_gcc_tree/lib/gcc/aarch64-none-elf/8.2.1/crtbegin.o"

Diff for: clang/test/Driver/arm-toolchain.c

@@ -17,6 +17,7 @@
 // C-ARM-BAREMETAL: "-isysroot" "{{.*}}Inputs/basic_arm_gcc_tree/armv6m-none-eabi"
 // C-ARM-BAREMETAL: "-internal-isystem" "{{.*}}Inputs/basic_arm_gcc_tree/armv6m-none-eabi/include"
 // C-ARM-BAREMETAL: "{{.*}}/Inputs/basic_arm_gcc_tree/lib/gcc/armv6m-none-eabi/8.2.1/../../../../bin/armv6m-none-eabi-ld"
+// C-ARM-BAREMETAL: "--sysroot={{.*}}/Inputs/basic_arm_gcc_tree/armv6m-none-eabi"
 // C-ARM-BAREMETAL: "-Bstatic" "-EL"
 // C-ARM-BAREMETAL: "{{.*}}/Inputs/basic_arm_gcc_tree/armv6m-none-eabi/lib/crt0.o"
 // C-ARM-BAREMETAL: "{{.*}}/Inputs/basic_arm_gcc_tree/lib/gcc/armv6m-none-eabi/8.2.1/crtbegin.o"
@@ -54,6 +55,7 @@
 // CXX-ARM-BAREMETAL: "-internal-isystem" "{{.*}}/Inputs/basic_arm_gcc_tree/armv6m-none-eabi/include/c++/8.2.1"
 // CXX-ARM-BAREMETAL: "-internal-isystem" "{{.*}}/Inputs/basic_arm_gcc_tree/armv6m-none-eabi/include"
 // CXX-ARM-BAREMETAL: "{{.*}}/Inputs/basic_arm_gcc_tree/lib/gcc/armv6m-none-eabi/8.2.1/../../../../bin/armv6m-none-eabi-ld"
+// CXX-ARM-BAREMETAL: "--sysroot={{.*}}/Inputs/basic_arm_gcc_tree/armv6m-none-eabi"
 // CXX-ARM-BAREMETAL: "-Bstatic" "-EL"
 // CXX-ARM-BAREMETAL: "{{.*}}/Inputs/basic_arm_gcc_tree/armv6m-none-eabi/lib/crt0.o"
 // CXX-ARM-BAREMETAL: "{{.*}}/Inputs/basic_arm_gcc_tree/lib/gcc/armv6m-none-eabi/8.2.1/crtbegin.o"
@@ -92,6 +94,7 @@
 // CXX-ARM-BAREMETAL-LIBCXX: "-internal-isystem" "{{.*}}/Inputs/basic_arm_gcc_tree/armv6m-none-eabi/include/c++/v1"
 // CXX-ARM-BAREMETAL-LIBCXX: "-internal-isystem" "{{.*}}/Inputs/basic_arm_gcc_tree/armv6m-none-eabi/include"
 // CXX-ARM-BAREMETAL-LIBCXX: "{{.*}}/Inputs/basic_arm_gcc_tree/lib/gcc/armv6m-none-eabi/8.2.1/../../../../bin/armv6m-none-eabi-ld"
+// CXX-ARM-BAREMETAL-LIBCXX: "--sysroot={{.*}}/Inputs/basic_arm_gcc_tree/armv6m-none-eabi"
 // CXX-ARM-BAREMETAL-LIBCXX: "-Bstatic" "-EL"
 // CXX-ARM-BAREMETAL-LIBCXX: "{{.*}}/Inputs/basic_arm_gcc_tree/armv6m-none-eabi/lib/crt0.o"
 // CXX-ARM-BAREMETAL-LIBCXX: "{{.*}}/Inputs/basic_arm_gcc_tree/lib/gcc/armv6m-none-eabi/8.2.1/crtbegin.o"